FV?w  n.   m^^  — 


UBRART 

Technical  Series,  No.  26.  ff  ATE  PL/iNT  BOARD 

U.  S.  DEPARTMENT   OF   AGRICULTURE, 

BUREAU    OF    ENTOMOLOC^-. 
L.  0.   HOWARD,   Entomologist  and  Chief  of  Bureau. 


AMERICAN  BLACK  FLIES 
OR  BUFFALO  GNATS. 


BY 


J.  R.  MALLOCH, 

Entomologica  1  Assistant . 


Issued  April  6,  1914. 


WASHINGTON: 

GOVERNMENT  PRINTING  OFFICE 

56' 

1914. 

2^3 

As£ 

Technical  Series,  No.  26. 

U.  S.  DEPARTMENT   OF   AGRICULTURE, 

BUREAU    OF    ENXOIVtOLOG-Y. 

L.  0.   HOWARD,    Entomologist  and   Chief  of  Bureau. 


AMERICAN  BLACK  FLIES 

OR  BUFFALO  GNATS. 


BY 


J.  R.  MALLOCH, 

Entomological  Assistant. 


Issued  April  6,  1914. 


WASHINGTON: 

GOVERNMENT  PRINTING  OFFICE. 

1914. 


BUREAU  OF  ENTOMOLOGY. 

L.  O.  Howard,  Entomologist  and  Chief  of  Bureau. 

C.  L.  Marlatt.  Entomologist  and  Acting  Chief  in  Absence  of  Chief. 

R.  S.  Clifton,  Executive  Assistant. 

W.  F.  Tastet,  Chief  Clerk. 

F.  H.  Chittenden,  in  charge  of  truck  crop  and  stored  product  insect  investigations. 

A.  D.  Hopkins,  in  charge  of  forest  insect  investigations. 

W.  D.  Hunter,  in  charge  of  southern  field  crop  insect  investigations. 

F.  M.  Webster,  in  charge  of  cereal  and  forage  insect  investigations. 

A.  L.  Quaintanck,  in  charge  of  deciduous  fruit  insert  investigations. 

E.  F.  Phillips,  in  charge  of  bee  culture. 

A.  F.  Burgess,  in  charge  of  gipsy  moth  and  brown-tail  moth  investigations. 

Rolla  P.  Currie,  in  charge  of  editorial  work. 

Mabel  Colcobd,  in  charge  of  library. 


LETTER  OF  TRANSMITTAL. 


U.  S.  Department  of  Agriculture, 

Bureau  or  Entomology, 
Washington,  D.  C,  October  20,  1913. 
Sir:  I  have  the  honor  to  transmit  herewith  a  manuscript  entitled 
"American  Black  Flies  or  Buffalo  Gnats,"  by  J.  R.  Malloch,  an 
entomological  assistant  in  this  bureau.  This  paper  deals  with  a 
group  of  flies  of  considerable  economic  importance.  As  pests  to  man 
and  domestic  animals  certain  species  of  the  group  have  long  attracted 
attention  in  this  country  and  elsewhere.  Recently  additional  inter- 
est in  these  insects  has  been  created  by  the  theory  that  certain  species 
transmit  pellagra.  This  theory  has  not  been  proven  and  it  is  not 
accepted  by  the  great  majority  of  investigators.  Nevertheless  the 
importance  of  the  buffalo  gnats  as  pests  to  man  and  domestic  animals 
is  so  great  that  accurate  information  regarding  the  species  which 
exist  in  this  country  is  highly  desirable.  This  paper  includes  de- 
scriptions of  several  species  new  to  science  and  in  other  respects  adds 
very  materially  to  our  knowledge.  I  recommend  the  publication 
of  this  manuscript  as  Technical  Series  No.  26  of  the  Bureau  of 
Entomology. 

Respectfully,  L.  O.  Howard, 

Entomologist  and  Chief  of  Bureau. 
Hon.  D.  F.  Houston, 

Secretary  of  Agriculture. 

3 


Digitized  by  the  Internet  Archive 
in  2013 


http://archive.org/details/americanblackfliOOmall 


CONTENTS. 


Page. 

Introduction 7 

Characters  of  the  group 7 

Generic  synonymy 11 

Unrecognizable  species  and  synonyms 12 

Table  of  genera 14 

Table  of  larvae 14 

Table  of  pupae 15 

Prosimulium  Roubaud 15 

Generic  characters.     Table  of  species 16 

Prosimulium  pleurale,  new  species 17 

Prosimulium  fulvum  Coquillett 18 

Prosimulium  hirtipes  Fries 18 

Prosimulium  mutatum,  new  species 20 

Prosimulium  pecuarum  Riley 21 

Parasimulium,  new  genus 24 

Parasimulium  furcatum,  new  species 24 

Simulium  Latreille 25 

Table  of  males 25 

Species  groups  in  Simulium  Latreille  (females) 26 

Group  A.     Table  of  species 26 

Simulium  aureopunctatum,  new  species 27 

Simulium  hippovorum,  new  species 28 

Group  B.     Table  of  species 29 

Simulium  trivittatum,  new  species 30 

Simulium  distinctum  Malloch 30 

Simulium  ochraceum  Walker 30 

Simulium  bivittatum,  new  species 31 

Simulium  notatum  Adams 32 

Group  C.     Table  of  species 34 

Simulium  mexicanum  Bellardi 35 

Simulium  parnassum,  new  species 36 

Simulium  arcticum,  new  species 37 

Simulium  bracteatum  Coquillett 38 

Simulium  exiguum  Roubaud 39 

Simulium  clavipes,  new  species 40 

Simulium  jenningsi,  new  species 41 

Simulium  venustum  Say 43 

Simulium  piscicidium  Riley 45 

Simulium  tarsale  Williston 46 

5 


6  AMERICAN   BLACK   FLIES    OR   BUFFALO    GNATS. 

Simulium  Latreille — Continued.  Page. 

Group  D.     Table  of  species 47 

Simulium  metallicum  Bellardi 48 

Simulium  meridionale  Riley 49 

Simulium  tamaulipense  Townsend 51 

Simulium  griseum  Coquillett 52 

Simulium  vittatum  Zetterstedt 53 

Simulium  pictipes  Hagen 55 

Simulium  virgatum  Coquillett 57 

Simulium  hunteri,  new  species 59 

Simulium  glaucum  Coquillett 60 

Group  E.    Table  of  species 1 61 

Simulium  quadrivittatum  Loew 61 

Simulium  haematopotum,  new  species 62 

Addenda: 

Simulium  forbesi,  new  species 63 

Simulium  johannserii  Hart 65 

Simulium  meridionale  Riley  and  its  allies 66 

Catalogue  of  North  American  and  Central  American  Simuliidae 68 

A  list  of  the  principal  papers  dealing  with  the  life  histories  of  American 

Simuliidae 69 

Index  to  genera  and  species 71 


ILLUSTRATIONS 


Page. 

Plate  I.  Anatomical  details  and  wing  venation  of  Simuliidae 72 

II.  Legs  and  tarsal  claws  of  Simuliidae 74 

III.  Larval  characters  of  Simuliidae 76 

IV.  Respiratory  filaments  of  pupae  of  Simuliidae 78 

V.  Anatomical  details  of  Simuliidae 80 

VI.  Anatomical  details  of  Simuliidae 82 


AMERICAN  BLACK  FLIES  OR  BUFFALO  GNATS. 


INTRODUCTION. 

Both  in  Europe  and  in  America  some  of  the  species  of  the  family 
Simuliidae  have  for  years  been  regarded  as  being  among  the  worst  of 
insect  pests,  and  in  some  cases  as  a  menace  to  the  lives  of  cattle  and 
even  of  human  beings.  The  common  species,  Simulium  colwribacz- 
ense  Schonbauer,  of  southern  Europe,  has  the  reputation  of  being 
very  destructive  and,  if  credence  be  given  to  records,  it  certainly 
equals  the  evil  reputation  of  any  other  bloodsucking  species  in  so 
far  as  the  effects  of  its  attacks  on  cattle  are  concerned.  Lately  there 
has  been  a  suggestion  made  that  some  species  of  this  group  may 
be  the  transmitter  of  pellagra,  and  it  is  to  ascertain  how  man}' 
American  species  occur  (in  so  far  as  our  material  permits)  and  their 
range  that  this  work  has  been  undertaken.  That  there  are  more 
species  than  are  listed  or  described  in  this  paper  there  can  be  no 
doubt,  but  in  view  of  the  fact  that  the  early  stages  of  the  species 
are  passed  in  streams,  from  which  it  is  not  easy  to  remove  them 
and  successfully  rear  them  under  artificial  conditions,  a  number  of 
closely  allied  species  have  not  been  so  far  linked  up  in  the  adult, 
pupal,  and  larval  stages.  It  is  essential  to  the  existence  of  the  larva? 
that  they  shall  remain  in  water  in  which  there  is  a  current,  and 
removal  to  water  in  a  jar  or  vessel  generally  kills  them  after  a  few 
hours.  The  material  available  for  study  for  the  purposes  of  this 
paper  consists  of  the  collection  in  the  U.  S.  National  Museum  and 
a  few  specimens  kindly  loaned  by  Prof.  O.  A.  Johannsen  and  Mr. 
C.  W.  Johnson.  Much  of  the  material  in  the  National  Museum  was 
collected  by  Messrs.  A.  H.  Jennings  and  W.  V.  King  in  connection 
with  the  pellagra  investigations  in  North  Carolina  and  South 
Carolina  in  1912. 

It  is  not  considered  necessary  to  rewrite  the  history  of  the 
Simuliidae  in  this  paper,  but  a  bibliography  is  given  on  page  69 
of  the  principal  papers  on  the  American  species  in  the  group,  which 
may  be  consulted  with  reference  to  the  biology  of  the  species. 

CHARACTERS  OF  THE  GROUP. 
EGGS. 

The  eggs  are  deposited  in  many  cases  on  blades  of  grass,  twigs,  or 
leaves  of  trees  which  are  dipping  in  running  water.    According  to 


8  AMERICAN   BLACK   FLIES   OR  BUFFALO   GNATS. 

observations  by  Jennings  and  King  the  females  select  a  twig,  leaf, 
or  blade  of  grass  which  is  suitable,  and  approaching  the  margin  of 
same  nearest  the  water  commence  ovipositing  thereon.  The  number 
of  eggs  deposited  is  very  large,  and  generally  several  females  ovi- 
posit on  the  same  leaf,  the  combined  weight  of  the  eggs  serving  to 
submerge  the  leaf  or  blade  of  grass  and  provide  the  necessary  con- 
ditions for  the  emergence  of  the  larvae.  It  has  been  placed  on  record 
that  the  species  which  oviposit  on  rocks  have  the  faculty  of  entering 
the  water  to  oviposit  on  the  submerged  rock  surface.  The  egg 
masses  on  rocks  are  of  very  considerable  extent  and  must  amount 
to  thousands  in  number.  When  first  deposited  they  are  covered  with 
a  peculiar  slimy  coating  and  being  pale  yellowish  in  color  are  very 
conspicuous,  but  later  on  they  become  darkened  and  whether  on 
leaves  or  rocks  are  not  so  noticeable.  It  has  been  stated  by  Horvath  a 
that  the  female  lays  from  5,000  to  10,000  eggs.  This  is  undoubtedly 
an  exaggeration,  and  the  estimate  was  probably  arrived  at  by  con- 
sidering the  accumulated  mass  deposited  by  a  number  of  females  as 
being  the  deposit  of  only  one.  The  eggs  are  elongate-oval  and  are 
very  closely  packed  together  on  whatever  surface  they  may  be 
deposited.  The  egg  stage  occupies  about  a  week,  but  is  affected  by 
weather  conditions  and  also  by  the  date  of  deposition. 

LARVA. 

The  larvrc  are  cylindrical  in  shape,  attenuated  in  the  middle,  and 
thickened  at  each  end,  most  distinctly  on  the  posterior  third.  In 
length  they  vary  from  about  8  to  15  mm.  and  possess,  besides  the 
head,  12  segments.  They  vary  considerably  in  color,  being  almost 
entirety  black  in  pictipes  and  pale  yellowish-white,  with  slightly 
darker  cross-bands  on  the  segments,  in  venustum.  The  chief  charac- 
ters of  use  in  distinguishing  the  species  are  found  in  the  mouthparts. 

The  head  (PI.  VI,  fig.  1)  is  chitinized  and  slightly  flattened.  On 
each  side  there  are,  in  all  the  species  which  I  have  examined,  two 
irregularly  shaped,  black,  approximated  eye-like  spots.  On  the 
dorsal  surface,  well  forward  and  near  to  the  bases  of  the  fans,  are 
situated  the  three-jointed  antennas  (see  PL  VI,  fig.  3).  The  fans 
(PI.  Ill,  fig.  5)  are  composed  of  a  large  number  of  rays  (PI.  VI, 
fig.  7)  which  vary  in  number,  and  generally  in  structure,  in  the 
di  fforent  species.  The  function  of  these  fans  seems  to  be  that  of  guid- 
ing food  into  the  mouth  cavity,  moving  on  an  articulated  stalk  and 
meeting,  when  brought  forward  closed,  over  the  mouth  opening. 
The  mandibles,  which  in  most  cases  furnish  characters  in  their  denta- 
tion for  differentiating  the  species  (PI.  Ill,  figs.  1,  2),  are  situated 
lower  on  the  head  than  the  fans,  and  move  so  as  to  close  pincers- 

1  "  Le   mouchcron   de  Columbateh."     Rovart.   Lapok.,   1    Band,   pp.    195-204. 


CHARACTERS    OF    THE    GROUP:    LARVA.  9 

like  over  the  oral  orifice.  The  maxillae  (PI.  Ill,  fig.  0),  which  an: 
situated  below  the  mandibles  and  nearer  the  center  of  the  mouth, 
arc  useful  also  in  separating  the  larvae  of  the  different  species,  though 
the  characters  are  difficult  to  see.  The  labium  is  heavily  chitinized, 
and  presents,  in  the  toothing  of  its  anterior  margin,  characters  which 
appear  to  be  constant  and  of  a  more  accessible  and  a  more  easily 
appreciable  nature  than  either  the  teeth  of  the  mandibles,  the  shape 
and  bristling  of  the  palpi,  or  the  structure  of  the  antenna?.  This 
organ  (PI.  Ill,  fig.  3)  presents  in  the  two  species  of  Prosimulium 
(hirtipes  and  pecuccritm) ,  which  have  been  described  in  the  larval 
stage,  a  variation  in  the  structure  of  the  teeth  which  is  clearly  dis- 
tinguishable from  that  of  any  of  the  larvae  of  the  genus  Simulium 
with  which  I  am  acquainted.  In  these  two  species  the  central  tooth 
is  trifid,  and  the  other  teeth  are  irregularly  bifid,  or  at  least  not 
simple  as  in  the  species  of  Simulium.  Johannsen,  on  plate  35  in 
his  work  on  this  group,  figures  the  labium  of  a  species  from  Leland 
Stanford.  Jr.,  University  campus,  which  very  probably  is  that  of 
a  Prosimulium.  It  is  generally  unsafe  to  accept  distinguishing 
generic  characters  of  this  nature  without  an  extended  examination 
of  a  large  amount  of  material,  and  I  have  not  used  this  in  my  dif- 
ferentiation of  these  genera,  but  it  is  obvious  that  it  is  permissible 
to  indicate  its  existence  and  possible  significance. 

In  addition  to  the  mouth  parts,  already  indicated  as  of  importance 
in  the  separation  of  the  species,  it  will,  I  believe,  be  found  by  careful 
examination  that  the  other  parts  with  which  I  have  not  dealt  in  this 
paper  supply  characters  of  very  considerable  importance.  On  the 
ventral  surface  of  the  first  segment  is  an  elongated,  rounded,  and 
slightly  conical  proleg,  the  apex  of  which  is  furnished  with  a  number 
of  rows  of  hooks.  This  proleg  is  used  by  the  larva  in  its  movements 
from  place  to  place  in  much  the  same  manner  as  the  larvae  of  the 
Geometridae  use  the  legs  on  their  anterior  segments,  and  their  method 
of  progression  is  somewhat  similar  to  the  well-known  "  loopers  "  of 
this  family  of  moths.  When  disturbed,  the  larva  releases  its  hold 
on  the  rock  or  other  surface  and  floats  down  stream  attached  by  its 
proleg  to  a  silk  thread  which  it  emits  from  the  mouth,  regaining 
its  former  position  by  means  of  this  thread.  At  the  anal  end  is  a 
sucker-like  disk,  around  the  margin  of  which  are  arranged  concentric 
circles  of  minute  hooks  similar  to  those  at  the  apex  of  the  proleg. 
It  is  by  means  of  this  anal  process  that  the  larva  attaches  itself  to 
the  silk  threads  which  it  spins  on  the  surface  of  rocks  or  plants  in 
the  bed  of  the  stream.  On  the  dorsal  surface  of  the  last  abdominal 
segment  there  is  a  slit-like  opening  from  which  the  blood  gills  are 
projected.  (PI.  VI,  fig.  6.)  These  are  retractile  and  vary  in  form 
in  the  different  species. 


10  AMERICAN   BLACK    FLIES   OR  BUFFALO   GNATS. 

A  more  extended  description  of  the  larva,  with  a  consideration  of 
the  uses  of  the  various  organs,  is  given  by  Johannsen  (Bui.  68,  X.  Y. 
State  Museum,  1903,  pp.  345-350),  but  in  the  present  paper  it  is  only 
considered  necessary  to  indicate  the  position  of  the  various  organs 
used  in  the  descriptions. 

The  larval  stage  occupies  about  four  to  five  weeks  in  summer,  but 
cold  weather  retards  growth,  and  some  species  are  known  to  pass  the 
winter  in  this  stage.  When  full  grown  the  larva  spins  a  cocoon,  in- 
side of  which  it  transforms  to  the  pupa.  These  cocoons  are  differ- 
ently shaped  in  some  of  the  species.  In  the  case  of  pictipes  the  cocoon 
somewhat  resembles  a  slipper  in  shape  (PL  VI,  fig.  8),  in  venustum 
it  is  more  like  a  conical  pocket,  while  in  Mrtipes  it  can  hardly  be 
called  a  cocoon,  being  simply  an  aggregation  of  threads,  the  work  of 
many  individuals  congregated  together  on  the  rock  surface,  amongst 
which  the  larvae  transform  to  pupa?,  and  by  which  they  are  more  or 
less  covered. 

PUPA. 

The  principal  character  by  means  of  which  the  pupae  of  the  differ- 
ent species  may  be  distinguished  is  the  number  of  respiratory  fila- 
ments (PI.  IV,  figs.  1-6;  PL  VI,  figs.  4,  5).  These  organs  are  situ- 
ated on  the  anterior  portion  of  the  thoracic  dorsum  and  consist  of 
from  4  to  60  branches.  The  number  is  generally  constant  in  each 
species,  but  when  there  is  a  very  large  number  of  filaments  it  happens 
occasionally  that  there  may  be  a  slight  variation  in  numbers  in  indi- 
vidual specimens.  In  addition  to  these  respiratory  organs  as  a 
means  of  identification,  there  are  situated  on  the  abdomen  a  number  of 
small  hooks  on  some  of  the  dorsal  and  also  on  some  of  the  ventral 
segments,  which  serve  as  a  means  for  the  retention  of  the  pupa  in  its 
cocoon  and  which  vary  in  number  in  the  different  species. 

IMAGO. 

In  the  male  the  eyes  are  very  large,  coming  closely  together  above 
and  leaving  no  distinct  frontal  stripe ;  the  upper  half  has  the  facets 
very  much  larger  than  the  lower,  from  which  they  are  distinctly 
divided  by  a  horizontal  line.  The  female  has  the  eyes  distinctly  sepa- 
rated above,  from  antennae  to  vertex,  by  a  more  or  less  posteriorly 
divergent-sided  frontal  stripe,  and  the  eye  facets  are  of  almost  uni- 
form size,  showing  more  or  less  tendency  to  become  larger  toward 
the  underside  in  some  species.  The  ocelli  are  absent  in  both  sexes. 
The  antennae  (PL  VI,  fig.  2)  are  11-jointed  (various  authors  have 
given  them  as  10-jointed),  the  basal  joint  generally  short,  the  second 
elongated  and  separated  by  a  more  distinct  constriction  from  the 
third  than  exists  between  any  of  the  other  joints,  the  third  joint  gen- 
erally subequal  in  length  with  the  second.     The  palpi  (PL  V,  fig.  9) 


GENERIC    SYNONYMY.  11 

are  four- jointed.  The  mouthparts  of  the  female  are  chitinized  and 
projecting,  being  adapted  for  piercing;  the  male  has  the  mouthparts 
much  more  rudimentary. 

The  thorax  is  peculiarly  formed,  and  the  most  remarkable  feature 
about  it  is  the  very  great  development  of  the  scutum  and  the  conse- 
quent reduction  of  the  prescutum.  The  diagram  given  on  Plate  I, 
figure  1,  will  serve  to  show  this  clearly.  The  presence  of  such  a  large 
membranous  field  on  the  pleurae  is  also  remarkable.  The  mesonotum 
has  always  a  surface  covering  of  pilosity,  which  varies  in  color  and 
also  very  much  in  distribution  and  in  form  in  the  different  species. 
These  characters  are  of  considerable  importance  and  are  extensively 
used  in  this  paper.  There  is  a  group  of  hairs  situated  on  the  upper 
portion  of  the  mesopleura  between  the  wing  base  and  the  base  of  the 
haltere,  which  is  throughout  this  paper  referred  to  as  the  pleural  tuft. 
Immediately  behind  the  posterior  spiracle  there  is  an  area  which 
sometimes  bears  hairs ;  this  I  have  called  the  post-spiracular  area. 

The  abdomen  has  been  considered  as  consisting  of  from  seven  to 
nine  segments  by  various  authors,  and  though  I  have  always  found 
eight  present  there  is,  besides  this  number,  a  loose,  scale-like  appen- 
dage at  the  base,  which  most  authors  consider  as  the  basal  abdominal 
segment.  I  am  not  certain  of  the  homology  of  this  part,  and  while 
I  consider  it  really  abdominal  (as  against  thoracic),  I  have  in  this 
paper  consistently  referred  to  it  as  the  basal  scale,  and  considered  the 
abdomen  as  possessing,  in  addition  to  this,  eight  distinct  segments. 
No  work  has  been  done  with  the  genitalia  in  this  group  and,  owing  to 
the  nature  of  these  organs,  it  would  require  very  careful  work  and 
plenty  of  fresh  material  to  make  a  successful  study  of  them.  They 
are  not  normally  so  situated  as  to  be  of  use  in  identifications. 

The  legs  are  strong,  and  the  tarsi  generally  well  developed,  the 
fore  and  hind  pairs  being  generally  broad  and  the  metatarsi  very 
much  elongated.  The  last  three  tarsal  joints  are  as  shown  on  Plate 
V,  figure  10.  In  most  species  there  is  an  extension  at  the  apex  of  the 
hind  metatarsus,  and  in  the  species  with  this  process  there  is  generally 
a  corresponding  modification  of  the  second  joint,  which  is  explained 
in  my  remarks  on  the  genera.  The  claws  of  the  male  are  trifid,  of  the 
female  simple,  bifid,  or  with  subbasal  tooth.  The  wings  are  very 
broad  and  the  venation  is  peculiar,  resembling  Scatopse  in  some  re- 
spects.    (For  venation  see  PI.  I,  figs.  1^.) 

GENERIC   SYNONYMY. 

The  generic  name  Simulium  was  created  by  Latreille1  with  one 
species  included.  This  species,  Rhagio  colombaschensis  Fabricius, 
must  be  accepted  as  the  type  even  though  Latreille  in  volume  14  of 
the  same  publication  (1805.  p.  294)  indicates  that  this  species,  in  his 

1  Hist.  Nat.  Crust,  et  Ins.,  vol.  3,  1802,  p.  426. 


12  AMERICAN   BLACK   FLIES   OR   BUFFALO   GXATS. 

opinion,  is  synonymous  with  reptans  Linnaeus.  In  Catalogus  Dip- 
terorum,  volume  1. 1902,  page  288,  colombaschense  Fabricius1  is  given 
as  a  synonym  of  maeulatum  Meigen.2  I  can  not  understand  the  reason 
for  this,  unless  it  be  that  the  name  columbaczense  Schonbauer3  has 
obtained  such  currency  that  there  is  a  disinclination  to  replace  it 
by  a  new  name,  should  the  slight  difference  in  spelling  be  accounted 
insufficient  to  distinguish  the  species.  Thus  it  is  evident  that 
Sim/ulhim  is  a  well-authenticated  genus. 

The  resurrection  of  Meigen's  paper  of  1800 4  did,  however,  tempo- 
rarily alter  conditions,  and  the  suggestion  has  been  made,  and  acted 
upon  in  some  cases,  that  Melusina  Meigen  should  supplant  Simulium 
Latreille.  That  I  have  not  accepted  this  view  is  due,  not  to  the  fact 
that  there  were  no  species  included  in  the  genus,  but  that  the  first 
species  cited  as  belonging  to  it,  Tipuld  regelationis  Linnaeus,5  is  that 
which  was  given  as  the  type  of  Atractocera  Meigen.  The  placing  of 
this  species  in  Atractocera  by  Meigen  was  probably  based  upon  a 
misidentification ;  still  the  species,  which  is  now  considered  as  a 
Trichocera  Meigen,6  must  be  accepted  as  the  type  of  Atractocera 
Meigen,  and  as  this  genus  is  given  for  the  first  time  by  Hendel '  as 
synonymous  with  Melusina  Meigen,  it  follows  that  Melusina  must 
be  accepted  as  the  generic  name  of  the  group  to  which  regelationis 
Linnaeus  belongs.  In  other  words,  both  Atractocera  Meigen  and 
Trichocera  Meigen  must,  if  we  strictly  adhere  to  the  rules  governing 
zoological  nomenclature,  be  considered  as  synonyms  of  Melusina 
Meigen.  Thus  I  am  able,  by  adhering  to  the  strict  letter  of  the 
law,  to  retain  the  name  best  known  and  most  generally  used  for  the 
family.  The  question  of  the  retention  of  Trichocera  Meigen  as  the 
generic  name  for  the  group  containing  regelationis  Linnaeus  I  shall 
leave  to  others  to  decide  upon;  it  is  not  within  the  scope  of  this  paper 
to  discuss  more  than  the  validity  of  the  names  used  within  the 
Simuliidae. 

UNRECOGNIZABLE    SPECIES    AND    SYNONYMS. 

In  practically  every  family  of  Diptera  there  are  species  which  it  is 
impossible  to  identify  from  the  original  descriptions,  and  in  no  family 
is  this  more  apparent,  with  the  possible  exception  of  the  Chironomidse 
in  Great  Britain,8  than  in  the  Simuliidae.  The  species  are  so  similar 
in  general  appearance  and  the  tangible  characters  are  so  difficult  to 


1  Mantissa  Ins.,  vol.  2,  1787,  p.  335,  No.  15. 

2  Klass.,  vol.  1,  1804,  p.  05,  No.  3,  Atractocera. 

3  Gesch.  d.  schiidl.  Kolumb.  Miicken,  Culex,  1705. 

4  Nouv.  Class.  Mouch. 

*Illlg.  Mag.,  vol.  2,  1803,  p.  203. 

6  Illig.  Mag.,  vol.  2,  1803,  p.  262. 

7  Voi-lianrtl.  zool.-bot.  (Jos.  in  Wien,  vol.  58,  1008,  p.  50. 

•Verrall,   in    his   list  of   British   Diptera.    1901.   places  !»:>   of   Walker's   species   of  Chi- 
ronomuH  among  the  "  unrecognizable  species." 


UNRECOGNIZABLE    SPECIES    AND    SYNONYMS.  13 

see,  even  with  a  magnification  of  over  GO,  that  in  many  cases  the  de- 
scribe^ failing  to  note  them,  has  written  a  description  which  might 
serve  equally  well  for  several  species. 

In  a  case  of  this  kind,  where  one  can  not  definitely  decide  which 
species  of  several  was  originally  described,  there  are  two  courses 
available,  failing  the  production  of  the  types :  Either  arbitrarily  fix 
on  one  of  the  species,  or  place  the  name  among  the  unrecognizable 
species.  Of  these  courses,  the  latter  has  been  most  generally  adopted 
with  Walker's  species,  and  though  Coquillett  linked  up  pecuarum 
Riley  with  invenustum  Walker,  and  vittatum  Zetterstedt  with  dec- 
orum Walker,  this  does  not  affect  the  matter  of  the  acceptance  of 
these  names,  as  the  first  is  quite  evidently  a  misidentification  of 
Walker's  species  and  Zetterstedt's  name  vittatum  has  priority  over 
Walker's  decorum.  Pecuarum  Riley  was  described  from  Louisiana, 
and  the  farthest  northern  record  I  know  for  this  species  is  Westville, 
Conn.,  while  invenustum  Walker  was  described  from  St.  Martins 
Falls,  Albany  River,  Hudson  Bay,  Canada.  The  specimens  which  I 
have  seen  from  Labrador  and  which  may  be  either  Walker's  species 
or  that  recorded  as  reptans  Linnaeus  b}^  Lundbeck,1  are  undoubtedly 
not  pecuarum.  The  only  species  of  Walker's  which  can  be  accepted 
with  any  degree  of  certainty  is  ochraceum.  In  this  case  the  coloration 
and  locality  prove  good  guides,  and  I  believe  I  am  correct  in  identify- 
ing the  specimens  from  Cordoba  as  belonging  to  the  species  Walker 
had  before  him  when  he  wrote  his  description. 

I  am  of  the  opinion  that  Coquillett  was  right  in  making  argus 
Williston  a  synonym  of  vittatum  Zetterstedt,  and  have  followed  him 
in  this.  Cinereum  Bellardi  I  have  not  seen  and  I  am  of  the  opinion 
that  it  will  be  very  difficult,  if  not  impossible,  to  recognize  it.  In  the 
case  of  the  species  minutum  Lugger,  I  believe  it  is  absolutely  impos- 
sible to  recognize  what  species  was  intended  and  have  followed 
Johannsen's  synonymy,  and  the  same  applies  to  that  author's  species 
irritatum.  Pulchrum  Phillipi 2  I  do  not  consider  as  identical  with 
tarsale  Williston,  and  I  reinstate  the  latter  name.  Reptans  Linnaeus 
I  do  not  believe  occurs  in  America,  and  I  have  not  included  it  in  my 
paper.  This  species  is  not  well  defined  even  in  Europe,  and  I  have 
been  unable  to  identify  any  American  specimens  with  either  of  the 
two  species  I  obtained  as  reptans  from  Britain,  either  or  neither  of 
which  may  be  the  true  reptans. 

Surcouf  and  Gonzales-Rincones 3  have  proposed  the  specific  name 
minutum  for  the  species  described  by  Dr.  Lutz  as  exiguumf  which 
name  is  preoccupied  by  exiguum  Roubaud.5    The  specific  name  minu- 

1  Diptera  groenlandica,  1898. 

2  Aufzahlung  der  chilenischen  Dipteren,  1865,  p.  633. 

3  Dipteres  vulnerantes,  vol.  1,  1911,  p.  290. 

4  Memoirs  d.  Instituto  Cruz,  vol.  1,  part  2,  1909,  p.  141. 

5  Bull.  Mus.  Paris,  1906,  p.  109. 


14  AMERICAN   BLACK    FLIES    OR   BUFFALO    GNATS. 

turn  is  also  preoccupied  by  a  species  recorded  by  Lugger,1  and  I  pro- 
pose for  this  species  the  name  lutzi.2 

TABLE    OF    GENERA. 

1.  Basal  joint  of  hind  tarsus  generally  distinctly  prolonged,  lappet-like,  on 

posterior  surface  at  apex ;  second  joint  with  basal  scale-like  process  and 

dorsal  excision;  radial  vein  unforked;  basal  cell  absent Simulium.  p.  25. 

Basal  joint  of  hind  tarsus  generally  but  little  produced  at  apex  pos- 
teriorly ;  second  joint  linear,  without  basal  scale  or  dorsal  excision ; 
radial  vein  generally  with  elongate  fork 2 

2.  Face  broad;  basal  cell  of  wings  distinct Prosimulium,  p.  15. 

dorsal  excision;  radial  vein  unforked;  basal  cell  absent Simulium. p. 25. 

TABLE    OF    LARVAE. 

The  following  table  of  larvae  has  been  arranged  to  include  all  the 
species  dealt  with  in  this  paper  which  have  been  associated  with  the 
adults. 

1.  Labium  with  the  central  tooth  trifid 2 

Labium  with  the  central  tooth  simple 3 

2.  Only  the  central  labial  tooth  trifid P.  pecuarum,  p.  23. 

All  teeth  except  the  outer  one  on  each  side  more  or  less  irregularly 

trifid P.  hirtipes,  p.  19. 

3.  Anal  blood  gills  simple,  three  in  number 8.  vittatum,  p.  55. 

Anal  blood  gills  subdivided 4 

4.  Large  species  (10-12  mm.  in  length),  almost  black  in  color. 

S.  pictipes,  p.  57. 
Smaller  larvae,  generally  yellowish  in  color,  with  more  or  less  distinct 
cross-bands  to  segments 5 

5.  Last  joint  of  maxillary  palpus  without  seta? £.  meridionale,  p.  51. 

Last  joint  of  maxillary  palpus  with  seta? 6 

6.  Labium  with  seven  pairs  of  setae  on  ventral  surface 8.  piscieidium,  p.  46. 

Labium  with  less  than  seven  pairs  of  setae 7 

7.  Labium  with  four  pairs  of  setae S.  jenningsi,  p.  42. 

Labium  with  five  pairs  of  setae S.  rcnustitm.  p.  44. 

The  foregoing  table  is  partly  constructed  from  that  given  by 
Johannsen  in  his  paper  on  the  group.  It  is  probable  that  there  are 
groups,  instead  of  single  species,  with  the  characters  given  in  this 
table  and  in  the  table  for  the  pupae  (p.  15),  but  until  some  one  with 
the  necessary  knowledge  of  the  anatomy  of  the  larva?  and  pupa?  de- 
votes considerable  time  to  their  study  our  knowledge  must  remain 
fragmentary  and  unsatisfactory.  It  is  also  probable  that  there  are 
some  species  which  are  not  possessed  of  tangible  distinctions  in  the 
imago  stage  which  may  be  easily  separated  in  either  the  larval  or 
pupal  stage. 

1.  48  Minn.  Agr.  Exp.  Sta.,  1896,  p.  202. 
•The  manuscript  of  this  paper  was  completed  in  December,  1912,  but  has  been  delayed 
in  its  appearance  In  print  from  various  causes.  In  the  number  of  "  Insecutor  Inscitise 
Mcnstruus"  for  December,  ]'.W.\,  there  appears  a  note  on  American  Simuliidae,  which 
drills  with  certain  matters  referred  to  in  this  and  preceding  pages.  The  writer  of  the 
note  referred  to  was  cognizant  of  the  existence  of  this  manuscript,  and  conversant  with 
its  contents,  winch  I  consider  do  not  accordingly  require  any  alteration  due  to  the  appear- 
ance Of  said  note. 


PROSIMULIUM.  15 

TABLE    OF    PUP-ffi. 

The  table  of  pupae  which  follows  is  arranged  to  include  only  the 
North  American  species  associated  in  this  stage  with  adults. 

1.  Respiratory  filaments  4  in  number £.  bracteatum,  p.  .°>9. 

8.  joh<nuis<  iti.  p.  66. 
Respiratory  filaments  more  than  4  in  number 2 

2.  Respiratory  filaments  6  in  number _ 3 

Respiratory  filaments  more  than  6  in  number. 

3.  Each  of  the  three  main  filaments  divided  close  to  base_S.  meridionale,  p.  GO. 
Each  of  the  three  main  filaments  divided  at  some  distance  from  base, 

8.  venustum,  p.  44. 

4.  Respiratory  filaments  8  in  number 5 

Respiratory  filaments  more  than  8  in  number 6 

5.  Filaments  in  pairs 8.  piscicidium,  p.  46. 

Filaments  not  in  pairs  (PI.  VI,  fig.  4) S.  metallicum,  p.  4!>. 

6.  Respiratory  filaments  9  in  number 8.  pictipes,  p.  57. 

Respiratory  filaments  10  or  more  in  number 7 

7.  Respiratory  filaments  10  in  number S.  jcnningsi,  p.  42. 

Respiratory  filaments  more  than  10  in  number S 

8.  Respiratory  filaments  16  in  number 8.  vittatum,  p.  55. 

Respiratory  filaments  at  least  22  in  number 9 

9.  Respiratory  filaments  22  to  25  in  number Sf.  forbesi,  p.  65. 

Respiratory  filaments  generally  more  than  40  in  number 10 

10.     Respiratory  filaments  at  most  48  in  number P.  pecua>-um,  p.  23. 

Respiratory  filaments  generally  60  or  more  in  number P.  hirtipes,  p.  20. 

In  addition  to  the  species  included  in  the  above  table  there  are  two 
species  described  in  this  stage  which  have  not  been  linked  up  with 
the  imago.  One  of  these,  from  Arizona.1  has  8  filaments,  and  the 
other,  from  Santa  Cruz  Mountains,2  has  12.  It  may  be  that  these 
species  are  described  in  the  imago  stage  and  have  not  yet  been 
associated  with  the  pupa?. 

Since  the  completion  of  the  manuscript  of  this  paper  I  have  had  the 
opportunity  of  working  over  the  material  in  the  collection  of  the 
Illinois  State  laboratory  of  natural  history  which  has  resulted  in  the 
addition  of  forbesl  to  the  list  of  species. 

PROSIMULIUM   Roubaud. 

Prosimulium  was  originally  proposed  as  a  subgenus  by  Roubaud.3 
The  characters  which  he  used  for  the  separation  of  the  group  from 
Simulium  Latreille  were  those  of  the  hind  tarsus  and  also  the  forma- 
tion of  the  cocoons,  which  he  considered  as  possessing  a  generic 
value  from  the  fact  that  they  are  incomplete,  a  mere  shapeless  mass 
of  threads,  whereas  in  Shnulhun  the  cocoons  in  the  known  species 
are    slipper-shaped    and    separately    formed.     It   may    be    that    his 

1  Trans.  Amer.  Ent.  Soc,  1893,  p.  45. 

2  Bui.  OS,  N.  Y.  State  Mus.,  1903,  p.  387. 
3Compt.  Rendus  Acad.  Sci.,  Paris,   1906,  p.  519, 


16  AMERICAN   BLACK   FLIES   OK   BUFFALO    GNATS. 

deductions  are  correct  with  regard  to  the  formation  of  the  cocoons 
of  this  genus,  but  on  the  other  hand  some  of  the  species  which  are 
unknown  in  the  early  stages  may  have  habits  similar  to  Simulium 
Latreille,  and  I  therefore  do  not  make  use  of  them,  preferring  to  use 
the  characters  furnished  by  the  venation  of  the  wings,1  which  was 
not  mentioned  by  Roubaud  in  dealing  with  the  group,  as  well  as 
those  of  the  hind  tarsus. 

As  I  have  already  pointed  out,  in  dealing  with  the  larval  charac- 
ters, it  is  not  improbable  that  the  labium  of  the  larvse  may  provide 
a  further  character  for  the  separation  of  this  genus  from  Simulium, 
though  that,  like  the  character  of  the  cocoon  formation,  requires 
further  study  before  being  accepted  as  a  generic  rather  than  a  specific 
character. 

Roubaud  states  that  the  claws  in  Prosimulium  are  all  of  one  type, 
"very  simple,"  and  also  that  the  species  are  confined  to  "high  alti- 
tudes or  cold  regions."  These  statements  are  not  in  accordance  with 
the  actual  facts  of  the  case,  as  he  included  pecuarum  Riley,  which 
has  bifid  claws,  and  was  originally  described  from  Louisiana,  as  one 
of  the  species  in  his  original  definition  of  Prosimulium.  It  is  always 
risky  to  generalize  upon  insufficient  data  or  material,  and  though  I 
possess  probably  a  much  larger  amount  of  material  than  Roubaud 
had,  I  consider  that  I  have  gone  as  far  as  my  material  justifies  me 
in  separating  the  genera  by  the  characters  given  in  my  table  and  in 
indicating  the  probable  significance  of  others  without  giving  them 
as  generic  distinctions. 

GENERIC    CHARACTERS. 

Eyes  in  male  large,  meeting  above,  the  upper  facets  much  larger 
than  the  lower  and  separated  by  a  horizontal  line ;  in  female  the  eyes 
are  separated  by  a  wide  and  more  or  less  divergent-sided  stripe. 
Antenna?  11-jointed;  palpi  4-jointed.  Wings  with  the  radial  vein 
furcate,  or  indistinctly  so,  or  simple  (mutatum),  and  a  small,  closed 
cell  near  wing  base  (PI.  I,  fig.  3).  Hind  tarsi  with  apex  of  first  joint 
very  slightly  produced  posteriorly,  except  in  mutatum,  and  second 
joint  linear  (PL  II,  figs.  1,  2)  ;  tarsal  claws  tridentate  in  male,  in 
female  simple  (PL  II,  fig.  13),  or  with  the  base  produced  thumblike 
(PL  II,  figs.  14,  1G). 

Type  of  genus. — Simulium  hirtipes  Fries. 

TABLE   OF    SPECIES. 

L     Eyes  widely  separated  above  (females) 2 

Eyes  closely  coherent  above  (males) 6 

2.     Tarsal  claws  with  base  produced  into  an  elongated  projection,  bifid 3 

Tarsal  claws  with  base  only  slightly  tubercnlate  or  rounded,  simple 4 

1  I  have  Included  in  this  genus  mutatum,  which  has  the  radius  simple,  and  pecuarum, 
Which  has  it  very  Indistinctly  furcate,  preferring  to  retain  the  former  here  instead  of 
erecting  another  genus  for  it. 


PROSIMULIUM.  17 

3.  Furcation    of    radial    vein    very    short    and    ill-defined;     niesopleurse 

bare pecuarum,  p.  21. 

Furcation  of  radial  vein  distinct  and  elongate;  mesopleurae  with  dis- 
tinct hairs pleurale,  p.  IT. 

4.  Yellow  species fulvum,  p.  18. 

Black  species  with  gray  or  yellow  legs 1 5 

5.  Fork  of  radius  long  and  distinct hirtipes,  p.  IS. 

Radius  unforked mutatum,  p.  20. 

6.  Entirely  yellow  species fulvum,  p.  18. 

Black  species 7 

7.  Fork  of  radial  vein  very  short,  indistinct pecuarum,  p.  21. 

Fork  of  radial  vein  long  and  distinct Mrtipes,  p.  18. 

Prosimulium  pleurale,    new  species. 

Female. — Black-gray,  opaque.  Frons  and  face  whitish-dusted, 
antennae  brown-black,  palpi  concolorous.  Mesonotum  without  stripes 
or  distinct  pollinose  spots;  pleura?,  scutellum,  and  postscutum  con- 
colorous with  disk  of  scutum.  Abdomen  opaque,  black-gray.  Legs 
brownish-yellow;  all  tarsi,  and  especially  fore  pair,  and  apices  of 
tibiae  darkened.  Wings  grayish,  veins  brown,  thin  veins  rather 
more  distinct  than  usual.    Halteres  brownish-yellow. 

Frons  divergent-sided,  at  vertex  twice  as  wide  as  at  above  antennae, 
surface  thickly  covered  with  long,  soft,  white  hairs;  face  as  long  as 
frons  and  distinctly  longer  than  broad,  colored  as  frons  and  similarly 
haired;  antennal  pile  white,  hairs  on  palpi  brown,  postocular  cilia 
pale,  some  longer  brown  hairs  present  near  eye  margins.  Mesonotum 
with  long,  loose,  hairlike,  white  pilosity,  which  is  longer  on  the  an- 
terior lateral  angles  and  posteriorly;  a  few  longer,  dark,  upright  hairs 
on  posterior  fourth ;  pleural  tuft  white,  extending  almost  to  the  lower 
angle  of  the  epimerum ;  another  group  of  similarly  colored  hairs  oc- 
cupying the  lower  portion  of  episternum  (eps2)  ;  postspiracular  area 
pale-haired;  scutellum  with  long,  white,  upright  hairs  and  decum- 
bent white  pilosity.  Abdominal  basal  scale  brownish-yellow,  the 
fringe  whitish,  sides  of  all  segments  with  long,  silk}7,  white  hairs, 
disk  with  much  shorter  brown  hairs.  Legs  long,  with  white  hairs 
and  shorter  white  pilosity;  hind  tarsi  w^ith  basal  two  joints  of  the 
usual  form  in  this  genus;  claws  bifid  (PI.  II,  fig.  16).  Wings  with 
costal  divisions  beyond  subcostal  vein  2:f  :1J;  veins  fine  and  short- 
haired  ;  basal  wing  hairs  short,  brown. 

Length,  4  mm. 

Type. — Cat.  No.  15403,  U.  S.  National  Museum.  One  female, 
Kaslo,  British  Columbia  (R.  P.  Currie). 

The  early  stages  are  unknown.  The  situation  of  the  anterior 
pleural  hairs,  bifid  claws,  and  furcate  radius  should  readily  dis- 
tinguish this  species  from  any  other. 

16125°— 14 2 


18  AMERICAN    BLACK   FLIES   OR   BUFFALO   GNATS. 

Prosimulium  fulvum   Coquillett. 

Female. — Entirely  yellow  or  ocherous;  the  antennae  except  basal 
three  joints,  the  pleurae,  abdomen,  and  tarsi  more  or  less  brownish. 
Wings  yellowish,  the  veins  distinct.     Halteres  yellow. 

Frons  rather  strongly  divergent,  at  lower  angle  of  eyes  about  two- 
fifths  as  broad  as  at  upper  angle;  surface  hairs  long  and  numerous, 
golden  yellow  in  color;  face  slightly  broader  than  frons  at  lower 
angle  and  rather  longer  than  broad,  haired  as  frons;  palpi  brown- 
haired;  postocular  cilia  long,  yellow,  with  a  strong  admixture  of 
black  hairs.  Mesonotum  with  longish,  yellow,  hairlike  pilosity,  rather 
shaggy  on  anterior,  lateral,  and  especially  on  posterior  margins; 
pleural  tuft  yellow,  continued  downward  more  than  midway  to 
coxae;  scutellum  with  long  yellow  pilosity,  and  shaggy,  upright, 
yellow  hairs.  Abdomen  with  yellow  basal  fringe,  and  numerous 
short  yellow  surface  hairs.  Legs  with  long  yellow  hairs,  among 
which  are  a  few  dark  ones,  the  tarsal  hairs  brownish;  tarsal  claws 
simple  (PI.  II,  fig.  13).  Wings  with  surface  hairs  yellow,  the  small 
cell  at  base  of  upper  fork  of  cubitus  distinct. 

Length.  4-5  mm. 

There  are  females  in  the  collection  from  Sitka,  Virgins  Bay,  and 
Kukak  Bay,  Alaska ;  from  Bear  Lake,  Kokanee  Mountains,  Kaslo. 
South  Fork,  Lowes  Inlet,  and  Laggan,  British  Columbia,  and  Cus- 
ter County,  Colo. 

Male. — Similar  in  size  and  color  to  the  female,  but  with  much 
longer  hairs,  especially  those  forming  the  fringe  to  the  basal  scale, 
those  on  surface  of  abdomen,  and  those  on  the  legs.  The  fore  tarsus 
is  slender,  and  the  basal  joint  of  hind  tarsus  is  much  dilated,  being 
as  broad  as  the  apical  portion  of  hind  tibia  (PI.  II,  fig.  1)  ;  the 
claws  are  trificl. 

The  type  specimen  (Cat.  No.  6182,  U.  S.  National  Museum)  is 
from  Bear  Paw  Mountain,  Mont.,  September  3,  1805  (Hubbard). 

Nothing  is  known  of  the  life  history,  or  details  of  the  early  stages 
of  this  species,  and  there  are  no  records  of  whether  or  not  it  bites 
either  man  or  animals. 

Prosimulium    hirtipes    Fries. 

Female. — Black,  opaque.  Antennae  with  two  basal  joints  pale 
yellowish-brown.  Scutum  unstriped,  and  without  any  distinct  an- 
terior pollinose  spots;  prescutum  and  pleurae  sometimes  brownish. 
Abdomen  with  basal  scale  brownish;  sometimes  the  segments  appear 
faintly  whitish-dusted  on  posterior  margins.  Legs  brown;  coxae, 
knees,  tips  of  tibiae  and  tarsi,  especially  fore  tarsus,  darker.  Wings 
grayish.     Halteres  brown. 


PROSIMULIUM.  19 

Frons  divergent-sided,  occupying  less  than  one-third  the  width  of 
head  at  upper  angle  of  eyes,  and  two-thirds  as  wide  above  antennae 
as  at  upper  angle,  surface  covered  with  close-placed,  yellow,  hair- 
like pilosity;  face  slightly  narrower  than  frons  at  upper  angle  and 
distinctly  longer  than  broad,  haired  as  frons;  palpi  pale-haired, 
postocular  cilia  pale.  Scutum  covered  with  very  closely  placed 
yellow  pilosity,  which  is  much  longer  and  upright  on  posterior  fourth, 
no  black  hairs  present;  pleural  tuft  pale  yellow,  carried  almost  to 
lower  margin;  scutellum  with  decumbent. yellow  pilosity,  and  long, 
upright,  yellow  hairs.  Abdominal  basal  fringe  yellow,  all  segments 
covered  with  moderately  closely^  placed,  yellow,  hairlike  pilosity. 
Legs  with  yellow  pilosity,  and  similarly  colored  upright  dorsal 
hairs;  fore  tarsi  slender,  ioihts  without  apical  paired  hairs;  claws 
simple.  Fork  of  radius  distinct,  group  of  hairs  at  base  of  first  thick 
vein  yellow ;  beyond  this  the  hairs  on  surfaces  of  veins  are  brown. 

Length,  3.5-4.5  mm. 

Localities  of  specimens  examined:  Ithaca,  X.  Y.  (O.  A.  Johann- 
sen)  ;  Wellesley,  Mount  Tom,  and  Cohasset,  Mass.;  Cape  Charles, 
Newfoundland ;  Morristown  and  Germantown,  Pa. ;  Kingston, 
R.  I.;  Rigolet,  Labrador;  and  Moscow,  Idaho  (collection  C.  W. 
Johnson)  ;  Cabin  John,  Md.  (J.  R.  Malloch)  ;  White  Mountains, 
K.  H.  (Morrison);  Mount  Katahdin,  Me.;  Williams,  Ariz.  (H.  S. 
Barber)  ;  Kaslo  and  Laggan,  British  Columbia  (Dyar  and  Cau- 
dell)  ;  Plummers  Island,  Md.  (W.  L.  McAtee).  The  dates  of  cap- 
ture are  for  the  Eastern  States  confined  to  the  latter  part  of  April 
and  larger  part  of  May;  the  specimen  from  Arizona  was  taken  on 
June  3.  The  specimens  from  British  Columbia  bear  the  dates  July 
and  August,  one  from  Maine  (3,000  feet  level)  August,  and  the 
Newfoundland  and  Labrador  specimens  were  taken  in  July.  In  the 
collection  of  the  Illinois  State  Laboratory  of  Natural  History  there 
are  two  females  of  this  species  from  Algonquin,  111.,  one  of  which 
bears  the  date  April  29, 1895  (Nason). 

Male. — Similar  in  color  and  size  to  the  female,  but  as  a  rule  there 
is  less  tendency  to  have  the  base  of  the  antennas  and  portions  of  the 
legs  pale.  The  hairs  and  pilosity  are  much  darker,  being  uniformly 
brown,  or  yellowish  brown,  and  much  longer,  especially  the  basal 
fringe  on  abdomen.  The  hind  legs  are  much  more  dilated,  especially 
the  basal  tarsal  joint,  and  the  claws  are  trifid. 

There  is  no  indication  of  pollinosity  on  thorax  or  abdomen  in 
any  specimen  I  have  examined. 

Larva. — Yellowish  brown  in  color;  antennas  as  in  Plate  VI,  figure 
3,  mandibles  with  the  apical  teeth  black,  the  smaller  ones  yellowish; 
labium  with  the  teeth  mostly  trifid  (PL  III,  fig.  3).  The  maxilla  of 
the  larva  is  shown  in  Plate  III,  figure  6.    This  is  the  largest  species  yet 


20  AMERICAN   BLACK    FLIES   OR  BUFFALO    GNATS. 

found  in  this  stage  in  America.  It  occurs  in  the  early  months  of  the 
year — is  stated  by  some  observers  to  hibernate  in  this  stage — and 
pupates  at  the  end  of  April,  the  imago  emerging  in  about  10  days 
after  pupation  takes  place. 

Pupa. — This  species  may  be  known  in  the  pupal  stage  by  the  very 
large  number  of  respiratory  filaments  (PL  IV,  fig.  5).  These  num- 
ber as  high  as  60  in  some  cases,  but  as  is  generally  the  case  where 
there  is  a  multiplicity  of  branches  there  is  a  greater  tendency  to 
variation  in  number  than  with  the  species  which  have  only  a  few 
filaments.     Xo  distinct  cocoon  is  formed  by  this  species. 

This  fly  is  reported  to  be  a  very  persistent  biter  and  does  not  con- 
fine its  attentions  to  cattle,  but  attacks  human  beings  as  well. 

I  have  only  one  poorly  preserved  European  specimen  of  hirtipes 
before  me  and  can  not  find  any  characters  to  separate  it  from  the 
American  species.  They  may  be  identical,  but  only  a  knowledge  of 
the  early  stages  of  both  can  definitely  decide  this. 

The  species  figured  in  Bulletin  159,1  Kentucky  Agricultural  Ex- 
periment Station,  is  quite  evidently  hirtipes  and  not  pecuarum  Riley. 

There  are  several  specimens  in  collections  from  the  White  Moun- 
tains and  also  some  from  British  Columbia  which  have  the  legs 
yellow.  These  may  belong  to  a  different  species,  but  I  can  not  find 
any  distinguishing  characters  in  the  specimens  other  than  this,  which 
I  consider  is  too  prone  to  variation  to  prove  reliable. 

Prosimulium  mutatum,  new  species. 

Female. — Black-gray,  subopaque.  Only  the  prescutum,  posterior 
portions  of  pleurae,  and  legs  more  or  less  yellowish.  Mesonotum 
without  distinct  pollinosity,  and  unstriped.  Wings  grayish,  veins 
brown.     Halteres  brown. 

Frons  gray-dusted,  narrow,  slightly  divergent-sided,  occupying 
about  one-fifth  the  width  of  head  at  upper  angle  of  eyes,  a  distinct, 
central,  longitudinal  depression  over  antenna?,  surface  hairs  pale, 
sparse;  face  colored  as  is  frons,  a  little  longer  than  wide,  and  as  wide 
as  frons  at  upper  angle,  surface  hairs  pale ;  antennae  with  the  basal 
joints  not  distinctly  paler  than  remainder;  hairs  on  palpi  dark;  pro- 
boscis short ;  postocular  cilia  pale,  with  a  few  longer  black  hairs  inter- 
mixed. Mesonotum  with  sparse,  rather  widely  separated,  yellow, 
hair-like  pilosity;  posterior  fourth  of  scutum  with  a  few  upright 
black  hairs;  pleural  tuft  pale,  long,  confined  to  upper  fourth;  scu- 
tellum  with  pale  upright  pilosity  and  upright  brown  hairs.  Abdo- 
men with  pale  basal  fringe,  and  scattered  pale  surface  hairs,  which 
are  more  numerous  on  lateral  margins  and  apical  segments.  Legs 
with  pale  pilosity  and  dark,  longer,  upright  dorsal  hairs;  fore  tarsi 

«  Bui.   159,  Ky.  Agr.  Exp.  Sin.,  flg.  4,  p.  18;  fig.  5,  p.  20;  fig.  6.  p.  21,  1012. 


PROSIMULIUM.  21 

slender,  without  paired  apical  hairs;  fore  tibiae  with  weak  apical 
spur;  hind  tarsi  with  basal  joint  distinctly  produced  at  apex  (PL  II, 
fig.  18),  second  joint  without  scale  but  slightly  constricted  dorsally 
at  base;  tarsal  claws  simple.  Wings  without  fork  to  radius,  the 
small  closed  basal  cell  present;  hairs  on  wing  veins  brownish  black. 

Length,  3-4  mm. 

Type. — Cat.  No.  15404,  U.  S.  National  Museum. 

Type  locality,  Glassboro,  N.  J.,  March  28,  1910  (C.  T.  Greene). 
Paratypes  from  Clementon,  N.  J.,  May  7,  1910  (C.  T.  Greene)  ;  St. 
Louis,  Mo.,  April  6,  1904  (W.  V.  Warner)  ;  Kaslo,  British  Columbia 
(H.  G.  Dyar)  ;  Mount  Eainier,  Wash.  (M.  W.  Lyon,  jr.)  ;  Sitka, 
Virgins  Bay,  and  Yakutat,  Alaska,  Harriman  Alaska  Expedition 
(T.  Kincaid)  ;  Metlakatla,  Alaska.  There  is  a  specimen  of  this 
species  in  the  Illinois  State  Laboratory  of  Natural  History  collection 
from  Homer,  111.,  April  25,  1909. 

This  species  presents  some  characters  which  differ  considerably 
from  those  of  the  type  of  the  genus  (hirtipes),  but  I  do  not  consider 
it  necessary  to  create  a  new  genus  for  its  reception,  more  particularly 
because  at  least  one  character,  and  the  most  pronounced,  the  radial 
furcation,  is  only  indicated  to  a  slight  extent  in  pecuarum,  which 
is  clearly  congeneric  with  hirtipes.  Roubaud  in  subdividing  Si- 
mulium  used  the  tarsal  characters  and  did  not  cite  the  types  of  his 
genera.  His  Eusimulium  is  clearly  a  synonym  of  Simulium,  as  the 
characters  indicated  for  its  separation  from  Prosimulium  are  those 
possessed  by  the  type  of  that  genus,  and  the  only  species  mentioned 
by  Roubaud  as  an  example  of  Eusimulium  is  aureum  Fries,  which 
possesses  the  tarsal  characters  given  by  him.  He  evidently  consid- 
ered it  inadvisable  to  use  Simulium  as  the  name  of  one  of  his  di- 
visions, because  he  intended  only  to  make  use  of  these  as  subgenera, 
and  not  genera.  Surcouf  and  Gonzalez-Rincones x  have,  however, 
used  the  three  names  and  placed  in  the  genus  Eusimulium,  which 
they  characterize  as  having  the  "  second  hind  tarsal  joint  constricted," 
a  number  of  species  which  they  evidently  knew  only  from  the 
printed  descriptions.  In  Simulium  sens,  strict,  they  include  several 
species  which  they  evidently  have  never  had  an  opportunity  of  ex- 
amining, and  which  certainly  possess  the  same  tarsal  characters  as 
those  they  relegate  to  Eusimulium.  I  have  considered  Roubaud's 
genus  as  a  synonym  of  Simulium  and  also  consider  that  the  publica- 
tion above  referred  to  does  not  materially  affect  this  position.2 

Prosimulium  pecuarum  Riley. 

This  species  is  similar  in  color  and  size  to  mutatum,  but  differs  as 
follows:  The  pilosity  on  scutum  and  hairs  on  abdomen  are  whitish- 
yellow,  the  scutum  is  more  or  less  distinctly  three-striped,  the  hind 

1  Diptferes   vuleranis   dos   du    Venezuela,    I,    1912,    p.    276. 
-  See  footnote  3  to  p.  14. 


22  AMERICAN   BLACK   FLIES   OR   BUFFALO   GNATS. 

tarsus  has  the  basal  joint  but  little  produced  at  apex  (PL  II,  fig.  2), 
the  claws  are  bifid  (PI.  II,  fig.  14),  and  the  radius  is  very  indistinctly 
furcate  at  apex. 

The  species  was  originally  described  from  reared  specimens,  the 
larva?  and  pupse  of  which  were  stated  to  have  been  obtained  at  Frier- 
sons  Mill,  La.,  but  the  type  specimen  in  collection  is  from  a  lot 
obtained  by  Prof.  F.  M.  Webster  at  Somerset  Landing,  La.,  April 
10,  1886.  A  very  large  number  of  these  specimens  are  in  the  col- 
lection. There  is  also  a  series  of  specimens  from  Lake  View,  Miss., 
April  18, 1886;  one  specimen,  College  Station,  Tex.,  (F. M.Webster) ; 
four  specimens,  Arkansas,  May  6,  1886  (Lugger),  and  I  have  seen 
specimens  from  Westville,  Conn.,  April  25, 1907  (W.  E.  Britton) ,  and 
Iona,  X.  J.,  April  21,  1907  (collection  C.  W.  Johnson),  which  agree 
with  the  types,  except  in  being  rather  darker  in  color.  There  are 
several  females  of  this  species  in  the  Illinois  State  Laborator}^  of 
Natural  History  collection  from  Aledo,  111.,  April  30,  1891,  1  female 
from  Quiver  Lake  near  Havana  on  the  Illinois  Eiver,  April  30,  1895, 
and  1  female  from  Havana,  Illinois  Eiver,  April  14,  1896.  The 
record  of  Simulium  vittatum  from  Mount  Carmel,  111.,  April  9,  in 
the  Twenty-seventh  Eeport  of  the  State  Entomologist  of  Illinois, 
1912,  page  37,  refers  to  pecuarum. 

The  male  specimens  from  which  Eiley's  description  was  drawn  are 
not  among  the  material  in  the  collection,  and  those  mentioned  as 
being  in  Cornell  University  Museum,  by  Johannsen,  I  have  found 
upon  examination  are  females.  Thus,  I  have  had  to  copy  the  original 
description. 

3  .—Length  1.5  mtn.  to  2.2  mm.  Differs  considerably  from  female.  Head  not 
visible  from  above,  being  occupied  by  the  very  large  confluent  eyes ;  the  remain- 
ing parts  below  the  eyes  are  black,  with  black  hairs  and  bristles ;  eyes  composed 
of  two  different  kinds  of  facets,  those  above  being  very  large,  as  large  again  as 
those  of  the  female,  and  those  in  front  and  surrounding  the  dwarfed  tropin  very 
minute,  the  dividing  line  between  the  sizes  being  abrupt;  anteume  similar  to 
those  of  the  female,  more  pronounced  in  color,  both  the  black  and  reddish  being 
more  vivid ;  maxillary  palpi  black,  and  shorter  than  the  antennae.  Thorax  black 
above,  with  sparse  yellow  hairs ;  legs  somewhat  lighter  in  color,  tip  of  tarsi  not 
black ;  hairs  upon  legs  longer  than  in  those  of  female.  Wings  hyaline,  veins  and 
base  yellowish-brown.  Abdomen  black,  with  grayish-white  posterior  margins  to 
salients,  dorsally  and  laterally,  and  covered  with  longer  yellowish  hairs. 

Described  from  two  bred  specimens. 

This  species  is  known  popularly  as  the  "  buffalo-gnat,"  and  has  in 
the  past  proven  a  great  pest  to  cattle  in  the  South,  particularly  near 
to  the  Mississippi  and  Ohio  Eivers.  Very  few  recent  specimens  are 
in  the  collection  and  the  general  opinion  among  entomologists  seems 
to  be  that  it  is  much  less  common  than  in  former  years,  when  it  is 
recorded  as  having  been  so  numerous  and  so  persistent  in  its  attacks 
on  stock  as  to  kill  mules  and  cattle. 


PBOSTMULTUM.  23 

Riley's  description  of  larva,  pupa,  and  cocoon  follows: 

Larva.— Average  length  when  full  grown,  7  """.  to  8  mm.,  subcylindric,  the 
club-shaped  posterior  third  of  body  being  twice  as  stout  as  the  thoracic  joints, 
and  joint  4  the  most  constricted.  Translucent  when  living,  dirty  white  in 
alcohol.  Immaculate  in  a  very  few  specimens;  distinctly  marked  in  the  great 
majority  with  brownish  dorsal  cross-bands  in  middle  of  joints,  leaving  free  a 
white  mediodorsal  longitudinal  line;  thoracic  joints  with  three  irregular  rings  of 
the  same  color;  underside  more  or  less  irregularly  spotted  with  brown.  Head 
subquadrate,  horny,  yellowish-brown,  with  a  number  of  brown  spots  and  lines 
in  regular  order  as  in  figure,  and  two '  roundish,  approximate  ocellate  black 
dots  on  each  side  under  the  skin,  and  seemingly  rudimentary  organs  of  sight, 
from  which  the  future  compound  eyes  originate :  antennce  uniformly  pale, 
three-jointed,  about  one-third  as  long  as  greatest  width  of  head ;  joint  1  very 
stout,  fully  four  times  as  thick  as  2,  which  is  a  little  longer  than  1,  straight, 
slightly  tapering  towards  tip;  joint  3  extremely  small,  a  mere  triangular  tip: 
mentum  [labium]  subtriangular,  with  apex  cut  away  and  replaced  by  three 
groups  of  very  small  teeth,  of  which  the  central  group  consists  of  three  teeth, 
the  middle  one  largest,  and  the  groups  on  side,  of  four  teeth,  of  which  the 
second  from  center  is  largest;  sides  of  mentum  [labium],  near  apex,  with  two 
small  teeth  each ;  all  the  teeth  are  chitinous  and  black ;  a  long  erect  bristle, 
pointing  upward  and  inward,  near  each  side  of  mentum:  labram  horny, 
densely  covered  with  hair :  mandibles  resembling  in  shape  the  profile  of  the 
inverted  last  joint  of  the  human  thumb,  with  a  series  of  teeth  in  place  of  the 
nail ;  teeth  difficult  to  see,  owing  to  the  presence  of  five  distinct  brushes  of  hair; 
on  extreme  lower  tip  of  mandibles  three  large  teeth,  below  them  a  series  of 
eleven  slender  and  very  pointed  teeth,  of  which  the  first  two  are  the  smallest, 
teeth  3  to  9  increasing  and  teeth  10  and  11  gradually  decreasing  in  length;  a 
second  series  of  teeth  below  them  consists  of  two  triangular  teeth,  of  which  the 
first  is  largest:  maxilla  stout,  fleshy,  with  an  internal  thumb-shaped  lobe; 
maxillary  palpus  two-jointed,  first  joint  cylindric,  second  very  short,  crowned 
with  a  regular  circular  row  of  short  spines  or  warts:  labium  [hypopharynx] 
horny,  with  two  brushes  of  hair  above,  between  wrhich  is  a  very  small  Ugula, 
covered  with  a  small  brush  of  hairs;  fans  composed  of  a  stout  stem,  bearing 
about  forty-six  scythe-shaped  rays,  lined  on  the  inside  by  very  minute,  equi- 
distant, erect  hairs  of  equal  length.  Thoracic  proleg  faintly  four-jointed,  sub- 
conical,  retractile  (introversible),  very  thin  and  transparent,  crowned  with 
about  twenty  rows  of  short,  sharp  hooks,  apparently  arranged  in  a  circular 
manner;  the  hooks,  of  which  ten  are  in  each  row,  seem  to  be  movable  to  a 
certain  extent,  and  are  fastened  or  hinged  to  small  chitinous  rods  in  the 
epidermis.  Tip  of  abdomen  formed  by  a  subcylindrical  body  crowned  with  rows 
of  hooks.  Breathing  organs  below  these  hooks  and  on  the  upper  side  of  ab- 
domen; they  consist  of  three  short,  cylindrical,  soft  and  retractile  tentacles, 
which  connect  with  the  large  internal  trachea?.  In  full-grown  larvae  a  spot 
more  or  less  dark  is  seen  on  each  side  of  thoracic  joint ;  it  is  produced  by  the 
formation  of  the  coiled  breathing  tubes  of  the  future  pupa. 

Pupa. — Average  length  5  mm.  General  color,  wrhen  fresh,  honey  yellow; 
prothoracic  filaments  brown,  and  the  abdomen  dorsally  also  tinged  with  brown, 
except  on  mediodorsal  space ;  all  the  members  have  also  a  fine  brown  marginal 
line.  Prothoracic  filaments  consisting  of  six  main  rays,  issuing  from  the  basal 
prominence  and  subdivided  two  or  three  times,  so  that  in  most  cases  as  many 
as  forty-eight  terminal  filaments  can  be  counted.  [Fl.  IV,  fig.  1.]  Abdominal  joints 
3,  4,  and  5  each  with  eight  well  separated  dark-brown  and  anteriorly-recurved 
hooks,  the  four  on  each  side  separated  by  a  mediodorsal  space ;  those  on  joint  3 


24  AMERICAN   BLACK   FLIES   OR   BUFFALO   GXATS. 

less  conspicuous  than  those  on  joints  4  and  5;  joint  6  with  armature;  joints 
7.  8,  9,  and  also  subjoint  [anal]  less  distinctly  armed  near  anterior  margin 
with  a  continuous  dorsal  row  of  very  minute  posteriorly  recurved  points ;  ven- 
trally  joints  6,  7,  and  8  have  each  four  very  minute  anteriorly  recurved  hooks. 

Cocoon. — Average  length  3.5  mm.  Not  completely  made  and  not  entirely  cov- 
ering the  pupa,  but  tightly  surrounding  its  larger  portion.  Shape  very  irregu- 
lar, with  no  distinct  rim  at  the  upper  edge,  which  is  more  or  less  ragged.  The 
threads  composing  it  are  very  coarse,  and  the  meshes  rather  open  and  ordi- 
narily filled  with  mud.  Not  always  fastened  separately  to  objects,  but  fre- 
quently crowded  together,  without  forming,  however,  such  coral-like  aggregations 
as  in  some  of  the  Northern  species. 

The  species  figured  by  Garman  as  the  "  buffalo-gnat  "  (S.  pecuarum 
Eiley)  in  Bulletin  Xo.  159  of  the  Kentucky  Agricultural  Experiment 
Station,  1912,  page  18,  is  not  this  species  but  hirtipes  Fries. 

Note. — Unfortunately  the  bulk  of  the  material  in  the  collection  is  practically 
all  from  two  localities  and  there  are  no  males  in  either  lot.  Prof.  F.  M.  Web- 
ster's material,  which  included  males,  collected  subsequent  to  the  date  on  the 
type  lot,  from  the  following  localities :  Madison  and  Vinland,  Ark. ;  Cypress 
Mill,  Marble  Falls,  and  Devils  River,  Tex. ;  and  Wooster.  Ohio,  can  not  be 
found. 

PARASIMULIUM,  new  genus. 

This  genus  differs  in  the  female  from  Prosimulium  Eoubaud  in 
having  the  eyes  much  more  widely  separated  at  vertex,  in  having  the 
frons  much  higher  than  highest  level  of  eyes  when  viewed  from  the 
side,  in  having  the  face  linear,  in  having  the  eye  facets  gradually  en- 
larged as  they  descend,  and  in  the  absence  of  the  closed  cell  in  the 
wing  (see  PL  I,  fig.  4). 

The  male  is  unknown. 

Type  of  genus. — Parasimulium  furcatum,  new  species. 

Parasimulium  furcatum,  new  species. 

Female. — Black-brown,  shining.  Frons  shining  black,  undusted; 
face  black;  antennas  with  second  joint  black,  remaining  joints  yel- 
low; palpi  black.  Mesonotum  shining  black-brown,  paler  posteri- 
orly; prescutum  pale  yellowish-brown;  pleurae  brown.  Abdomen 
brown,  anal  organs  yellow.  Legs  pale  yellow.  Wings  grayish,  all 
veins  brownish,  base  of  wing  very  pale  yellowish-white.  Halteres 
with  brown  knob  and  yellow  stalk. 

Frons  very  broad,  widely  divergent  posteriorly,  clothed  with  long, 
close-lying,  yellow-white  hairs;  face  very  narrow7,  linear,  raised  ridge- 
like centrally,  surface  brown-haired;  antennae  inserted  at  above  half 
the  height  of  eyes,  the  basal  joint  very  short  and  indistinct,  the  second 
joint  Large,  third  joint  slightly  longer  than  second,  and  as  long  as 
fourth  and  fifth  together,  fourth  longer  than  fifth,  fifth  to  tenth 
subequal,  eleventh  longer  than  tenth,  pilosity  pale,  very  short. 
Scutum  covered  with  close-lying  yellow  hairs  except  on  posterior 
third    where  it  narrows  and  has  only  scattered,  longer,  upright  hairs 


SIMULIUM.  25 

on  the  surface;  prescutum  with  upright,  rather  strong,  brownish 
hairs;  pleural  tuft  indistinct;  scutellum  with  pale  brown,  upright 
hairs  on  posterior  margin;  postscutum  produced.  Basal  abdominal 
scale  yellowish-brown,  fringe  white,  abdominal  segments  with  scat- 
tered pale  hairs.  Legs  with  weak  pale  hairs;  no  distinct  apical  tibial 
spurs;  hind  tarsi  as  in  Prosimalium,  tarsal  bristles  very  weak;  claws 
short  and  stout,  simple.  Wings  with  long  hairs  on  thick  veins,  vena- 
tion as  in  Plate  I,  figure  4. 

Length,  1.25  mm. 

Type. — Cat.  No.  15405,  U.  S.  National  Museum. 

One  female,  Bairs  Ranch,  Redwood  Creek,  Humboldt  County,  Cal. 
(H.  S.  Barber). 

Nothing  is  known  of  the  early  stages  of  this  species. 

SIMULIUM   Latreille. 
TABLES   OF   MALES. 

As  most  of  the  species  are  known  in  the  female  sex  only,  it  is  not 
possible  to  include  all  the  species  described  from  North  America  in 
this  table. 

1.  Species  with  noticeable  yellow  marks  on  abdomen  or  thorax 2 

Species  mostly  black,  only  the  legs  and  antennae  with  yellow  markings.      3 

2.  Small    species,    1    mm.,    mostly    yellow    colored;    scutum    indistinctly 

striped notation,  p.  33. 

Larger  species,  1.5  to  2  mm.,  mostly  black  colored;  scutum  distinctly 
striped distinct um,  p.  30. 

3.  Legs  with  basal  joint  of  hind  tarsus  not  bicolored 4 

Legs  with  basal  joint  of  hind  tarsus  bicolored 5 

4.  Pilosity  of  scutum  whitish a 

Pilosity  of  scutum  golden  yellow,  or  brassy b 

a.  Scutum  unstriped ;  dorsal  excision  and  scale  on  second  joint  of 

hind  tarsus  indistinct mcridionale,  p.  49. 

Scutum  with  black  stripes  as  in  female,  the  outer  one  on 
each  side  curved;  second  joint  of  hind  tarsus  with  distinct 
scale johannseni,  p.  65. 

b.  Pilosity  of  scutum  and  abdomen  brassy,  scale-like bract  eatum,  p.  38. 

Pilosity  of  scutum  yellow,  hairlike,  especially  hairlike  on  abdo- 
men  forbesi,  p.  64. 

5.  Small  species    (not  more  than  2  mm.  in  length)  ;  mid  tarsus  mostly 

yellow 6 

Larger  species   (at  least  2  mm.  in  length)  ;  mid  tarsus  with  at  most 
bases  of  first  and  second  joints  pale. 

6.  Scutum  almost  entirely  covered  with  pearlaceous  pollinosity ;  one  dis- 

tinct, opaque  black,  central  stripe  present griseum,  p.  53. 

Scutum  with  two  anterior  pearlaceous,  posteriorly  incurved,  elongate 
spots,  disk  velvety  black jenningsi,  p.  42. 

7.  Scutum  with  distinct  stripes 8 

Scutum  with  at  most  two  posteriorly  incurved  spots  on  anterior  margin.     10 


26  AMERICAN   BLACK   FLIES   OR  BUFFALO   GNATS. 

S.  Stripes  on  scutum  curved,  the  outward  extremities  of  dorso-lateral 
pair  dilated;  legs  with  a  narrow  black  or  brown  ring  or  spot  near 
base  of  tibiae  in  addition  to  the  usual  dark  marks  present  on  the  legs 
in  most  species virgatum,  p.  58. 

Stripes  on  scutum  straight,  legs  with  the  bases  of  tibiae  pale,  and  with- 
out a  subbasal  dark  band 9 

9.  Stripes  on  scutum  not  sharply  defined,  the  central  black  stripe  broad  at 
anterior  extremity,  linear  on  disk,  the  outer  black  stripes  short  and 
narrow glaucum.  p.  60. 

Stripes  on  scutum  generally  sharply  defined,  the  black  always  broader 

than  the  white  stripes vittatutn,  p.  54. 

10.     Only  two  posteriorly  incurved,  elongate  spots  on  anterior  margin;  fore 

tarsus  distinctly  dilated venustmn,  p.  44. 

In  addition  to  the  two  spots  just  mentioned,  there  are  sometimes  pres- 
ent two  smaller  spots  on  the  anterior  margin  nearer  to  center  and 
occasionally  also  faint  indications  of  a  central  bifid  stripe;  fore 
tarsus  very  slightly  dilated pictipes,  p.  56. 

I  have  not  seen  the  males  of  Simulium  metallicum  Bellardi,  S.  cin- 
ereuin  Bellardi,  nor  S.  mexicanum  Bellardi,  but  translations  of  the 
original  descriptions  are  given  under  the  descriptions  of  these  species. 

SPECIES  GROUPS  IN  SIMULIUM  LATREILLE    (FEMALES). 

1.  Mesopleura  with  a  group  of  hairs  in  addition,  and  anterior  to  the  normal 

pleural  tuft Group  A,  p.  20. 

Mesopleura  bare  except  for  the  pleural  tuft 2 

2.  Yellow  species ;  scutum  with  brown,  or  white  longitudinal  stripes,  or 

two  discal  elongated  spots;  abdomen  and  legs  with  black  or  brown 

marks * Group  B,  p.  29. 

Black  or  gray  species,  scutum  and  abdomen  never  yellow  (cf.  griseum)-      3 

3.  Scutum  with  three,  or  five  stripes,  or  only  one  central  stripe,  either  black 

or  brown  on  a  gray  ground,   or  metallescent  pollinose  on  a   black 
ground,  the  dorso-lateral  pair,  when  present,  distinctly  curved,  and 

dilated  at  anterior  extremities Group  D,  p.  47. 

Scutum  with  two,  or  four  broad,  white,  straight,  or  very  slightly  curved 
stripes,  which  are  nearly  parallel-sided  and  not  noticeably  dilated  at 
anterior  extremities,  or  scutum  unstriped 4 

4.  Scutum   unstriped  or  with  only  very  slight  indications  of  a   central, 

darker,   divided   stripe Group  C,  p.  34. 

Scutum  distinctly  striped,  the  stripes  white  or  metallescent  polli- 
nose  Group  E,  p.  61. 

Tt  is  not  the  intention  of  the  writer  to  indicate  from  the  above 
arrangement  that  these  groups  are  entitled  to  treatment  as  sub- 
genera; the  purpose  in  separating  them  thus  is  merely  to  facilitate 
the  work  of  identification  of  the  species. 

GROUP   A. 

Species  with  hairs  on  pleurae  in  addition  to  and  anterior  to  the 
pleura]  tuft. 


SIMULIUM.  27 

TABLE  OF   SPECIES. 

1.  Claws  with  minute  subbasal  tooth;  thoracic  pilosity  golden  yellow,  ir- 
regularly arranged  in  small  groups;  mesopleural  hairs  situated  low- 
down aureopunctatum,  p.  27. 

Claws  simple;  thoracic  pilosity  not  arranged  in  groups,   regularly  dis- 
posed ;  mesopleural  hairs  high  up  near  to  margin  of  scutum. 

Mppovorum,  p.  28. 

I  have  seen  very  few  species  of  Simuliidae  with  the  additional 
pleural  hairs,  but  one  of  those  I  have  obtained  as  reptans  Linnaeus, 
from  Britain,  another  in  the  collection  labeled  S.  lineatum  Meigen, 
variety,  and  also  subnigrwm  Lutz,  are  in  this  category,  though  no  one 
who  has  previously  described  any  species  in  the  family  has  ever  indi- 
cated that  he  has  noticed  the  presence  of  these  hairs  or  scales. 

Simulium  aureopunctatum,  new  species. 

Female. — Black,  subopaque.  Frons  and  face  with  whitish  dust- 
ing; antennas  brown,  two  basal  joints  yellow,  palpi  black.  Scutum 
unstriped,  slightly  whitish-dusted  anteriorly,  but  without  dis- 
tinct white  spots;  prescutum  and  margin  of  scutum  close  to  it  yel- 
lowish; pleurae  black-brown,  scutellum  and  postscutum  concolorous 
with  scutum.  Abdomen  black-brown,  basal  four  segments  subopaque, 
apical  four  shining.  Legs  yellow,  blackened  as  follows:  Entire 
ventral  surface  and  apical  half  of  dorsal  surface  of  tibiae,  and  entire 
tarsi  of  fore  pair ;  coxae,  femora  except  bases,  apical  halves  of  tibiae, 
apex  of  first,  apical  half  of  second  joint,  and  apical  three  joints  of 
tarsi  of  mid  and  hind  pairs.  Dorsal  surfaces  of  all  tibiae  with  dis- 
tinct silvering.  Wings  clear,  slightly  grayish  at  tip  and  on  hind 
margin,  thick  veins  brown.    Halteres  brownish  yellow,  stalk  darker. 

Frons  divergent-sided,  not  one-third  as  wide  at  upper  angle  of 
eyes  as  width  of  head,  distinctly  narrower  above  antennae  than  at 
upper  angle,  surface  hairs  black,  strong  but  not  numerous;  face 
slightly  convex,  distinctly  longer  than  broad,  and  slightly  broader 
than  frons  at  upper  angle,  surface  hairs  black,  on  upper  portion 
short  and  sparse,  longer  on  lowest  fourth;  palpi  black-haired,  post- 
ocular  cilia  brown.  Scutum  with  yellow  scale-like  pilosity  which  ad- 
heres closely  to  the  surface  and  is  arranged  in  irregular  groups  of  from 
three  to  seven  scales  of  uniform  length  except  on  posterior  fourth 
where  they  become  longer  and  are  more  upright ;  besides  this  pilosity 
the  surface  bears  numerous  short,  upright,  black  hairs  which  are 
most  conspicuous  on  anterior,  lateral,  and  posterior  margins ;  pleural 
tuft  brown,  the  anterior  pleural  hairs  golden  yellow,  scale-like,  situ- 
ated about  midway  from  lower  to  upper  margin  on  mesopleurae ;  post- 
spiracular  area  haired  posteriorly;  scutellum  with  yellow  scale-like 
pilosity  and  several  long,  upright,  blackish  hairs  on  posterior  mar- 
gin.    Basal  fringe  of  abdomen  long,  yellow,  surface  hairs  on  seg- 


28  AMERICAN   BLACK   FLIES   OR  BUFFALO   GNATS. 

ments  short,  black-brown.  Legs  strong;  fore  tarsi  compressed  later- 
ally, basal  joint  as  broad  as  tibia,  joints  1-3  with  paired  apical  hairs; 
all  legs  with  pale  pilosity  and  longer,  upright,  black  dorsal  hairs; 
apical  spur  absent  from  fore  tibiae,  hind  and  mid  pairs  with  paired 
apical  spurs;  basal  joint  of  hind  tarsi  as  broad  as  tibiae,  produced 
apically  on  posterior  surface,  claws  as  in  virgatum  (PI.  II,  fig.  11). 
Wings  with  outer  two  thick  veins  joining  costa  very  close  together 
so  that  the  last  costal  division  is  very  indistinct. 

Length,  3-3.5  mm. 

Type  and  paratypes. — Cat.  No.  15406,  U.  S.  National  Museum. 

Localities:  Livingston,  Guatemala,  and  Cacao,  Trece  Aguas,  Alta 
Vera  Paz,  Guatemala,  April-May  (Barber  and  Schwarz). 

Nothing  is  known  of  the  early  stages  of  this  species. 

Simulium  hippovorum,  new  species. 

Female. — Black,  subopaque.  Frons  and  face  brownish,  thickly 
covered  with  white  pollinosity;  antennae  brown,  basal  two  joints 
and  base  of  third  joint  yellow;  palpi  brown.  Scutum  with  three 
stripes,  the  central  one  narrow,  the  lateral  pair  broader,  close  to  the 
central  one,  dilated  anteriorly  and  slightly  curved;  viewed  from 
above  in  front  the  whole  disk  of  scutum,  except  the  stripes,  is  whit- 
ish pollinose  and  also  the  prescutum;  viewed  from  above  and  be- 
hind, the  anterior  dilated  portion  of  the  lateral  stripes  is  conspicu- 
ously white  pollinose;  pleurae  distinctly  whitish  pollinose  except  on 
membranous  portion;  scutellum  opaque  brown;  postscutum  with 
silky  white  pollinosity.  Abdomen  brown-black,  opaque  on  basal 
four  segments,  subshining  on  apical  four.  Legs  yellow,  black  as 
follows :  Mid  and  hind  coxae ;  apices  of  tibiae  and  entire  tarsi  of  fore 
legs,  narrowly  at  apices  of  femora;  a  spot  at  bases  and  broadly  at 
apices  of  tibiae;  apices  of  first  and  from  middle  of  second  to  fifth 
joint  of  tarsi  of  mid  and  hind  legs.  Wings  clear,  thick  veins  brown. 
Halteres  yellow. 

Frons  divergent-sided,  at  upper  angle  occupying  one-fourth  the 
head  width,  above  antennae  two-thirds  as  wide  as  at  upper  angle, 
surface  hairs  brownish  yellow,  sparse  and  weak;  face  broader  than 
frons  at  upper  angle,  almost  subquadrate,  surface  hairs  more  numer- 
ous than  on  frons,  whitish ;  hairs  on  palpi  pale  brown ;  postocular 
cilia  pale,  with  an  admixture  of  longer,  blackish  hairs  on  upper  part 
behind  vertex.  Pilosity  of  scutum  rather  loose  and  upright,  whitish 
yellow,  hairlike,  the  posterior  fourth  with  a  number  of  longer,  up- 
right, blackish  hairs;  anterior  pleural  hairs  pale  and  hairlike,  close 
to  lateral  margin  of  scutum;  pleural  tuft  pale,  confined  to  upper 
fourth,  postspiracular  area  pale  haired.  Abdominal  basal  fringe 
pale  yellow;  surface  hairs  on  segments  sparse.  pale.  Legs  with  yel- 
low, close-lying  pilosity  and  longer,  upright,  black  dorsal  hairs; 
fore  tarsi  not  noticeably  thickened,  the  paired  apical  hairs  present 


SIMULIUM.  29 

on  joints  1  and  3:  hind  tarsus  of  the  normal  shape  for  this  genus; 
tarsal  claws  simple  (PL  II,  fig.  12).  Wings  with  dark  brown  hairs 
on  veins. 

Length,  4  mm. 

Type.— Cat.  No.  15407,  U.  S.  National  Museum. 

Locality:  Sierra  Madre,  Mexico,  head  of  River  Piedras  Verdes, 
altitude  about  7,300  feet.  In  ear  of  horse  (C.  H.  T.  Townsend), 
one  female. 

I  do  not  think  that  this  can  possibly  be  the  species  described  as 
cin&reum  by  Bellardi  from  Mexico,  which  is  stated  to  attack  horses. 

A  translation  of  Bellardi's  description  is  as  follows: 

Male  and  female:  Gray,  antennae  black,  first  joint  pale.  Thorax  fuscous 
and  gray  pollinose,  the  humeri  pale;  pleura  light  gray,  scutellum  pale  at  the 
tip;  halteres  white.  Abdomen  blackish.  The  front  coxae  pale,  the  middle  and 
hind  pairs  grayish  brown ;  the  femora  pale  at  base,  their  tips  black ;  tibiae 
black,  their  middle  section  pale;  front  tarsi  wholly  black,  the  middle  and  hind 
pairs  with  the  bases  of  first  and  second  joints  pale.  Wings  hyaline.  Length 
of  body  3  mm. ;  extent  of  wings  9  mm. 

It  is  possible  that  this  may  prove  to  be  identical  with  Mppovorum, 
but  Bellardi's  description  might  apply  to  more  than  one  species  in 
the  genus  equally  well.  I  consider  it  better  to  have  this  species 
clearly  described  and  give  it  a  name  by  which  it  may  be  distin- 
guished than  to  accept  it  as  Bellardi's  species,  which  may  very  prob- 
ably prove  to  be  something  entirely  different. 

The  early  stages  are  unknown. 

The  name  cinereum  was  preoccupied  when  Bellardi  used  it,  and 
the  change  of  name  introduced  by  Speiser  is  given  in  the  catalogue 
at  the  end  of  this  paper. 

GROUP  B. 

In  the  species  of  Group  B  the  thorax,  abdomen,  and  legs  are  mostly 
yellow.  The  ground  color  of  all  the  species  is  yellow,  with  the 
thorax  brown,  or  white,  vittate,  and  the  abdomen  and  legs  more  or 
less  darkened. 

TABLE  OF   SPECIES. 

1.     Scutum  with  three  dark  vittae 2 

Scutum  with  white  vittae  or  with  only  two  anterior  marginal  spots 3 

Scutum  with  three  chocolate-colored  stripes;   abdomen  much  obscured 

with  brown trivittatum,  p.  30. 

Scutum   with  three  deep  black  stripes;   abdomen  with  three  rows  of 

black distinctum,  p.  30. 

3.  Scutum  with  only  anterior  spots notatum,  p.  32. 

Scutum   vittate 4 

4.  Larger  species  (from  Mexico),  claws  with  subbasal  tooth. .ochraceum,  p.  30. 
Smaller  species  (from  New  Mexico  and  Colorado)  ;  claws  simple. 

bivittatum,  p.  31. 

Neither  the  males,  except  of  notatum  and  distinctum,  nor  the  early 
stages  of  any  of  these  species  are  known. 


30  AMERICAN   BLACK   FLIES    OR  BUFFALO    GNATS. 

Simulium  trivittatum,   new  species. 

Female. — Yellow,  opaque.  Frons  and  face  thickly  white-dusted; 
antennae  browned  from  third  joint  to  apex;  palpi  brown.  Scutum 
with  three  broad,  parallel-sided,  chocolate  colored  stripes,  the  central 
one  not  reaching  to  scutellum  and  the  lateral  pair  not  reaching  to 
anterior  margin;  posterior  margin  of  scutellum  darkened  in  center; 
space  between  the  stripes  white-dusted ;  pleurae  brown  on  center  and 
slightly  white-dusted ;  scutellum  yellow ;  postscutum  brown,  subsum- 
ing. Abdomen  with  basal  scale  yellow ;  segments  yellow,  with  opaque 
black-brown  marks  which  leave  very  little  of  the  yellow  ground  color 
visible,  apical  four  segments  not  so  much  darkened  as  basal  four. 
Legs  }Tellow,  black  as  follows:  Apices  of  tibiae  and  all  except  base 
of  tarsi  of  fore  pair;  apices  of  first  and  second  and  apical  three  joints 
of  mid  and  hind  tarsi ;  apices  of  femora  and  apices  of  tibiae  of  hind 
pair.     Wings  clear,  thick  veins  yellow.     Halteres  yellow. 

Frons  divergent-sided,  two-thirds  as  wide  at  above  antennae  as  at 
upper  angle  of  eyes,  surface  hairs  weak,  yellow;  face  longer  than 
frons  and  one-third  longer  than  broad,  surface  hairs  as  on  frons; 
postocular  cilia  pale.  Scutum  with  very  short  hairlike  yellow  pilos- 
ity;  pleural  tuft  yellow;  scutellum  with  yellow  pilosity  and  longer 
upright  brownish  hairs.  Basal  fringe  on  abdomen  yellow;  all  seg- 
ments with  short,  scattered,  yellow  hairs.  Legs  with  pale  pilosity 
and  scattered  longer  dorsal  hairs  on  tarsal  joints;  fore  tarsi  slightly 
thickened ;  tarsal  claws  simple.     Wing  venation  normal. 

Length,  2  mm. 

Type.— Cat.  No.  15408,  IT.  S.  National  Museum. 

Locality. — Tampico,  Mexico  (E.  A.  Schwarz). 

Readily  distinguishable  from  any  described  species,  except  dis- 
tinction, by  the  brown  vittate  scutum. 

Simulium  distinctum  Malloch. 

This  species  was  described  subsequent  to  the  completion  of  the 
present  paper,  but  the  description  appeared  some  time  ago  in  the  Pro- 
ceedings of  the  Entomological  Society  of  Washington,  1913,  page  133. 
It  is  unnecessary  to  reproduce  the  description  here.  S.  trivittatum 
closely  resembles  distinctum,  though  I  believe  they  are  distinct. 

Locality. — Devils  River,  Texas. 

A  specimen  from  Tamaulipas,  Mexico,  is  with  some  doubt  referred 
here  also. 

Simulium    ochraceum    Walker. 

Female, — Yellow,  opaque.  Fare  and  frons  brownish  yellow,  thickly 
white-dusted:  antenna'  yellow,  from  fourth  joint  to  apex  browned; 
palpi    black-brown.     Scutum    with   two   white   pollinose    vithe,   and 


SIMULIUM.  31 

laterally  beyond  these  stripes  a  pear-shaped  brown  mark  with  the 
narrow  extremity  toward  the  wing  base,  which  stops  short  of  the 
prescutum  and  does  not  touch  the  white  stripes;  pleurae  brownish; 
scutellnm  yellow.  Abdomen  wTith  the  apical  segments  more  or  less 
blackened  and  subshining.  Legs  yellow,  blackened  as  follows:  Mid 
and  hind  coxae;  fore  tarsi  except  base;  apex  of  first,  apical  half  of 
second,  and  entire  apical  three  joints  of  mid  tarsi ;  apices  of  femora, 
apical  half  of  tibiae,  apical  half  of  first  and  second,  and  entire  apical 
three  joints  of  tarsi  on  hind  legs.  Wings  clear,  thick  veins  yellow. 
Halteres  yellow. 

Frons  divergent-sided,  at  above  antennae  about  one-third  as  broad 
as  at  vertex,  bare  in  center,  laterally  and  more  broadly  posteriorly 
covered  with  golden  pilosity  and  among  the  pile  some  longer,  upright^ 
black  hairs;  face  one-third  longer  than  broad,  uniformly  but  not 
thickly  covered  with  short,  yellow  pilosity ;  antennal  pilosity  whitish ; 
palpi  brown-haired;  postocular  cilia  mostly  yellow,  with  a  number 
of  longer,  black  hairs.  Stripes  on  scutum  as  broad  at  anterior  mar- 
gin as  the  space  between  them,  gradually  diverging  and  somewhat 
curved  posteriorly,  becoming  narrower  and  ceasing  at  a  little  be}7ond 
middle  of  disk ;  extreme  lateral  margins  of  scutum  whitish  pollinose, 
pilosity  golden  yellow,  scale-like  and  regularly  distributed ;  no  black 
hairs  on  scutum;  pleural  tuft  brown;  postspiracular  area  brown- 
haired  posteriorly;  scutellum  with  pale  yellow  pilosity  and  long,  up- 
right brown  hairs.  Abdominal  basal  fringe  pale  yellow,  long;  seg- 
ments with  scattered,  short  yellow  pile  and  a  few  longer  back  hairs 
intermixed  with  them.  Legs  with  close-lying  yellow  pilosity  and 
scattered,  longer,  upright,  dorsal  brown  hairs;  fore  tarsi  with  the 
normal  paired  apical  hairs  on  joints  1  and  3;  claws  as  in  Plate  II, 
figure  15.  Diagrams  of  the  thoracic  elevations  of  this  and  the  follow- 
ing twTo  species  are  shown  in  Plate  V,  figures  6-8. 

Length,  2  mm. 

Two  females,  Cordoba,  Mexico  (E.  Knab). 

The  records  of  the  occurrence  of  this  species  in  the  United  States 
which  I  have  had  the  opportunity  of  examining  are  erroneous  and 
refer  to  notatum  Adams.     (See  note  under  notatum,  p.  33.) 

Simulium  bivittatum,  new  species. 

Female. — Ocherous,  opaque.  Frons  and  face  thickly  white-dusted, 
antennae  from  apex  of  third  joint  to  apex  of  eleventh  browned, 
palpi  brown.  Scutum  with  two  broad,  almost  parallel-sided,  white- 
pollinose  vittae;  extreme  lateral  margins  of  scutum  white-pollinose ; 
prescutum  and  scutum  near  to  it  pale  yellow ;  pleurae  yellow,  browned 
on  middle ;  scutellum  ocherous ;  postscutum  black.  Abdomen  yellow, 
segments  2-G  Avith  a  distinct  black  dorsal  spot  and  brown  lateral 


32  AMERICAN   BLACK   FLIES   OR  BUFFALO   GNATS. 

marks,  apical  segments  subshining.  Legs  yellow,  browned  as  fol- 
lows :  Mid  and  hind  coxae ;  fore  tarsi  except  base ;  apices  of  first  and 
second  and  entire  apical  three  joints  of  mid  and  hind  tarsi;  and 
apices  of  hind  femora  and  tibiae.  Wings  clear,  thick  veins  yellow, 
costal  vein  darker.     Halteres  yellow. 

Frons  divergent-sided,  at  least  one-half  as  broad  above  antennae  as 
at  upper  angle  of  eyes,  surface  hairs  yellow ;  face  subquadrate,  nearly 
as  wide  as  frons  at  vertex;  surface  hairs  pale,  longer  toward  mouth 
edge;  antennal  pilosity  pale;  postocular  cilia  yellow.  Pilosity  on 
scutum  short,  regular,  golden  yellow,  longer  just  in  front  of  scu- 
tellum,  no  black  hairs  on  disk;  pleural  tuft  pale;  postspiracular  area 
pale-haired  posteriorly ;  scutellum  with  pilosity  and  upright  hairs  all 
yellow.  Basal  fringe  of  abdomen  pale,  apical  four  segments  with 
rather  distinct  pale  hairs.  Legs  haired  as  in  ochraceum.  Claws 
simple. 

Length,  1-1.5  mm. 

Type. — Cat.  Xo.  15415,  U.  S.  National  Museum. 

Locality  of  type,  East  Las  Vegas,  N.  Mex.,  June  1,  1901  (T.  D.  A. 
Cockerell).  There  are  also  in  the  national  collection  two  females 
from  Las  Vegas  Hot  Springs,  N.  Mex.,  August  19,  1901  (H.  S. 
Barber),  and  five  females  from  Virginia  Dale,  Colo.,  September  31, 
1912,  taken  on  cow  (Bishopp). 

Simulium  notatum  Adams. 

Female. — Ocherous  yellow,  opaque.  Frons  and  face  thickly  white- 
dusted;  antennae  slightly  darkened  from  fourth  joint  to  apex;  palpi 
ochreous.  Scutum  unstriped,  only  two  small  triangular  spots  on 
anterior  margin  and  very  faint  indications  posteriorly  of  the  stripes 
of  the  other  species,  laterally  a  darker  elongated  mark  on  disk ;  pre- 
scutum  and  margins  of  scutum  adjacent  to  it  yellow;  pleurae  dark- 
ened centrally,  more  distinctly  near  to  coxae;  scutellum  yellow;  post- 
scutum  black-brown.  xVbdomen  yellow ;  segments,  except  apical  three, 
with  opaque,  black  dorsal  spot,  apical  three  segments  slightly  shin- 
ing, their  bases  browned.  Legs  yellow,  browned,  or  blackened,  as 
follows:  I^ore  tarsi,  except  base  of  first  joint;  last  two  joints  of  mid 
tarsi;  extreme  apices  of  hind  tibia?;  and  apices  of  basal  three  and 
Avhole  of  apical  two  joints  of  hind  tarsi.  Wings  as  in  birittatum,  but 
the  costal  vein  paler.     TTalteres  yellow. 

Frons  divergent-sided,  two-thirds  as  wide  at  above  antennae  as  at 
upper  angle  of  eyes,  surface  hairs  weak,  sparse,  whitish;  face  sub- 
quadrate,  surface  hairs  as  on  frons;  antennal  pilosity  pale;  hairs  on 
palpi  pale;  postocular  cilia  pale.  Scutum  with  very  pale  yellow, 
hair-like  pilosity,  which  is  distinctly  longer  just  in  front  of  scutellum  ; 
pleural  tuft  pale;  scutellum  with  yellow  pilosity  and  upright  hairs. 


SIMULIUM.  33 

Basal  fringe  of  abdomen  pale  yellow,  surface  hairs  on  segments 
sparse,  pale,  longer  on  apical  segments,  and  more  numerous.  Legs 
with  pale  pilosity,  hairs  brown,  shorter,  and  not  so  numerous  as  in 
bivittatum,  the  paired  apical  hairs  on  first  and  third  joints  of  fore 
tarsi  shorter  than  in  that  species ;  claws  simple. 

Length,  1-1.5  mm. 

Three  females,  Las  Cruces,  N.  Mex.,  June  25,  1895  (T.  D.  A. 
Cockerell).  These  are  the  specimens  on  which  the  record  of  ochra- 
ceum  Walker  is  based  in  Entomological  News  for  1897,  page  100.  I 
have  not  seen  the  specimens  u^5ri  which  the  record  at  page  172  of 
the  same  volume  of  that  publication  was  based,  but  they  probably 
belong  either  to  this  species- or  to  bivittatvm. 

Male. — Brown.  Face'Avhite-dusted,  antennae  brown,  paler  on  basal 
two  joints,  palpi  brown.  Scutum  opaque,  evenly  covered  with  whitish 
gray  pollinosity ;  prescutum  and  adjoining  margin  of  scutum  yellow; 
pleurae  brownish  yellow,  whitish  pollinose ;  scutellum  yellow,  margins 
of  scutum  adjoining  scutellum  and  laterally  brown;  postscutum 
brown,  with  whitish  pollinosity.  Abdomen  yellow,  with  dorsum  of 
segments  1-2  narrowly,  and  remaining  segments  broadly  blackened, 
apical  three  segments  broadly  silvered  on  sides.  Legs  yellow,  browned 
on  fore  tarsi,  mid  and  hind  coxae,  apical  two  joints  of  mid  tarsi,  apices 
of  femora  and  apices  of  tibiae  of  hind  legs  (hind  tarsi  broken  off  in 
specimen)  ;  claws  trifid.  Wings  clear,  thick  veins  yellow,  venation 
normal.     Halteres  bright  yellow,  base  of  stalk  darkened. 

Eyes  with  upper  facets  very  large,  with  lower  facets  very  minute, 
hairs  on  face  and  palpi  pale,  postocular  cilia  weak,  pale.  Scutum 
with  close-lying,  whitish-yellow,  hair-like,  regular  pilosity,  which 
is  longer  in  front  of  scutellum ;  pleural  tuft  whitish ;  scutellum  with 
white  pilosity  and  longer,  upright,  white  hairs.  Abdominal  basal 
fringe  pale  yellow,  hairs  on  segments  sparse,  of  moderate  length, 
white.  Legs  with  sparse,  pale  pilosity  and  scattered,  longer,  pale 
hairs;  fore  tarsi  not  distinctly  thickened,  the  apical  paired  hairs 
weak;  hind  femora  and  tibiae  broad;  hind  tarsi  broken  off,  but  un- 
doubtedly possessing  the  normal  characters  of  Simulium. 

Length,  1  mm. 

Locality:  Williams,  Ariz.  (H.  S.  Barber),  one  male. 

It  may  be  that  this  is  really  a  distinct  species  from  the  female 
described  herewith,  but  there  are  so  many  points  of  agreement  that  I 
have  decided  to  consider  it  as  the  male  of  notatum  rather  than  describe 
it  as  new,  as  I  was  at  first  tempted  to.  The  only  point  which  causes 
me  to  doubt  the  safety  of  this  course  is  the  absence  of  any  indication 
of  the  white  pollinose  spots  on  the  scutum,  which,  if  the  general  rule 
holds  with  this  group,  ought  to  be  even  more  distinct  in  this  sex  than 
in  the  female. 

16125°— 14 3 


34  AMERICAN   BLACK   FLIES   OR  BUFFALO   GNATS. 

GROUP    C. 

Scutum  unstriped,  at  most  the  anterior  margin  with  weak  indica- 
tion of  a  central,  divided  stripe,  and  anterior  lateral  white  spots. 

TABLE   OF    SPECIES. 

1.  Tarsal  claws  with  a  distinct  subbasal  tooth  in  addition,  and  anterior, 

to  the  normal  tnberculate  or  rounded  base 2 

Tarsal  claws  without  subbasal  tooth,  only  the  base  tuberculate,  rounded, 
or  produced  thumblike  (as  in  PL  II,  figs.  5  and  7) 5 

2.  Thoracic  pilosity  arranged  in  irregular  groups,  disk  with  upright  black 

hairs,  in  addition  to  pilosity.  which  are  most  distinct  on  anterior 

angles mexicanum,  p.  35. 

Pilosity  not  arranged  in  groups,  regularly  disposed 4 

4.  Thoracic  pilosity  black  or  black-brown,  fine  and  hairlike parna-ssum,  p.  36. 

Thoracic  pilosity  lanceolate,  scalelike,  whitish  or  yellowish  in  color. 

arcticum,  p.  37. 

5.  Tarsal  claws  produced  thumblike  at  base 6 

Tarsal  claws  not  produced  thumblike  at  base 7 

G.     Scutum  with  brassy,  scalelike  pilosity ;  base  of  tibiae  not  blackened. 

bracteatum,  p.  38. 
Scutum  with  yellowish  hairlike  pilosity ;  base  of  tibiae  distinctly  black- 
ened   1  johannseni,  p.  G5. 

7.  Pilosity  on  scutum  arranged  in  punctiform  groups,  the  scales  short  and 

broad,  small  species exiguum,  p.  39. 

Pilosity  on  scutum  not  arranged  in  punctiform  groups,  either  regularly 
or  irregularly  disposed 8 

8.  Scutum  with  irregularly  disposed  golden  yellow  pilosity  and  upright 

brown  hairs  on  disk clavipes,  p.  40. 

Scutum  with  regularly  disposed  pilosity,  discal  hairs  absent 9 

9.  Small  species  (1-1.5  mm.  in  length)  ;  mid  tarsi  almost  all  pale;  third 

joint  of  hind  tarsi  pale;  scutum  with  pearlaceous  pollinosity. 

jenningsi,  p.  ±1. 
Larger  species  (2-4  mm.  in  length)  ;  mid  and  hind  tarsi  black,  except 

buses  of  first  and  second  joints;  scutum  with  whitish  pollinosity 10 

10.     Scutum  more  or  less  shining,  the  anterior  margin  at  center  with  indica- 
tions of  a  divided  stripe;  pilosity  yellow venustum,  p.  43. 

Scutum  not  shining,  no  indications  of  a  central  stripe ;  pilosity  whitish. 

piscicidium,  p.  45. 

Simuliwn,  tarsale  Williston  belongs  to  this  group,  but  from  the 
description  I  am  unable  to  place  it  in  the  table.  In  all  probability 
it  is  distinct  from  any  of  those  included  in  my  table,  but  nothing  is 
said  of  the  tarsal  claws  and  certain  other  essential  characters  in 
Williston's  description,  so  that  it  is  impossible  to  decide  its  status. 
The  species  belonging  to  this  group  are  the  most  widely  distributed 
and  most  closely  allied  of  the  Simuliidee.  It  is  to  this  segregate  that 
reptans  Linnaeus  and  several  other  European  species  belong. 

1  I  have  included  jolia  ,uiscii  i  here  :is  well  ns  in  the  group  with  vittnte  scutum,  as  it  is 
closely  allied  to  bracteatym  in  the  formation  of  the  claws,  but  the  coloration  as  given 
above,  though  of  alcoholic  specimens,  is  quite  distinct  from  that  of  bracteatum,  as  is  also 
the  vestiturc  of  the  thorax.     For  description  see  pp.  G5-66. 


SIMULIUM.  35 

Simulium   mexicanum   Bellardi. 

Female. — Black,  subopaque,  only  the  apical  four  abdominal  seg- 
ments distinctly  shining.  Frons  and  face  white-dusted;  antenna; 
brown,  with  basal  two  joints  and  base  of  third  joint  yellowish;  palpi 
brown.  Prescutum  yellowish,  pleura)  with  sutures  and  posterior 
portions  yellowish;  scutellum  brownish  yellow;  postscutum  brown, 
whitish  pollinose;  scutum  unstriped  and  weakly  white-dusted. 
Abdomen  with  basal  scale  opaque  black;  first  segment  below  scale 
yellow  or  brown  at  base,  opaque  black  at  apex;  segments  2-A  gray- 
ish pollinose,  with  opaque  black  fascia?,  which  are  broadest  at  middle 
and  taper  on  each  side;  apical  four  segments  glossy  black;  venter 
browmish  yellow.  Legs  black,  yellow  as  follows :  Coxa?,  femora,  and 
bases  of  tibia?  of  fore  pair;  apices  of  coxae,  trochanters,  bases  and 
apices  of  femora,  basal  halves  of  tibia?,  and  basal  halves  of  first  and 
second  joints  of  tarsi  of  mid  and  hind  pairs;  base  of  third  joint  of 
mid  tarsi.  Wings  grayish,  thick  veins  brown.  Halteres  yellow,  dark- 
ened at  base  of  stalk. 

Frons  almost  parallel-sided,  not  one-third  as  wide  at  vertex  as 
the  breadth  of  head,  surface  hairs  black;  face  longer  than  frons  and 
wider  than  frons  at  upper  margin,  one-third  longer  than  wide,  sur- 
face hairs  black ;  hairs  on  palpi  brown ;  postocular  cilia  black.  Scu- 
tum with  brassy  yellow,  scalelike  pilosity,  which  is  arranged  in  irregu- 
lar groups  on  the  disk ;  besides  the  pilosity  there  is  on  the  disk  short, 
closely  placed,  black,  upright  hairs,  which  are  most  distinct  on  the 
margins;  pleural  tuft  black  or  brown;  postspiracular  area  pale- 
haired;  scutellum  with  yellow  pilosity  and  longer,  upright  black 
hairs.  Basal  fringe  of  abdomen  yellow,  apical  four  segments  with 
short  black  hairs,  which  are  longer  at  extreme  apex.  Legs  with 
close-lying  yellow  pilosity  and  long,  upright,  black  dorsal  hairs, 
which  are  very  noticeable  on  the  apices  of  the  tarsal  joints;  fore  tarsi 
with  the  normal  paired  apical  hairs  on  joints  1  and  3;  the  legs  are 
strong  and  the  fore  tarsi  very  distinctly  thickened  or  compressed 
laterally;  tarsal  claws  with  subbasal  tooth  (PI.  II,  fig.  6). 

Length,  4  mm. 

Two  females,  Cordoba,  Mexico,  January  30,  1908  (F.  Knab). 

These  specimens  agree  so  closely  with  the  description  given  by 
Bellardi 1  that  I  have  no  hesitation  in  associating  them  with  his 
species.     The  early  stages  are  unknown. 

A  translation  of  Bellardi's  description  of  the  male  of  Simulium 
mexicanum  is  as  follows: 

Black.  Head  black,  frons  prominent,  triangular,  with  whitish  reflection: 
antennae  black,  first  joint  and  base  of  second  [second  and  base  of  third  ?J  yel- 
low ;  face  prominent,  black,  the  epistome  yellowish,  with  grayish  reflection ;  palpi 

1  Saggio  di  Ditterologia  Messicana,  App.  6,  1862. 


36  AMEKICAN   BLACK   FLIES   OR   BUFFALO   GNATS. 

black,  paler  at  the  base;  thorax  wide,  subquaclrate,  slightly  convex,  black,  with 
a  grayish  reflection,  and  golden  scales;  humeri  pale;  pleurae  black,  anteriorly 
and  posteriorly,  with  fuscous  spots;  scutelluni  fuscous;  halteres  white;  abdomen 
black,  base  of  second  segment  pale  yellowish  on  the  sides ;  fore  and  middle  coxae 
wholly  yellow,  hind  ones  fuscous,  with  yellow  tips;  fore  femora  wholly  yellow, 
mid  and  hind  pairs  fuscous-black,  with  yellow  bases;  fore  tarsi  wholly  black; 
middle  tarsi  black,  with  bases  of  all  the  joints  yellow ;  hind  tarsi  black,  with 
base  of  first  joint  broadly  and  of  second  joint  narrowly  yellow ;  wings  hyaline, 
iridescent.     Length  4  mm.,  alar  expanse  9  mm. 

Simulium   parnassum,    new    species. 

Female. — Black,  slightly  shining;  prescutum  paler;  pleurae  pale 
along  the  sutures;  abdomen  opaque  black  on  basal  four  segments, 
shining  on  apical  four;  legs  black,  yellowish  as  follows:  Coxa?,  tro- 
chanters, bases  of  tibiae,  and  base  of  first  joint  of  tarsi  of  fore  legs; 
apices  of  coxae,  bases  of  trochanters,  bases  of  femora,  of  tibiae 
narrowly,  and  of  first  tarsal  joint  of  mid  legs;  trochanters,  bases  of 
femora  and  of  tibia?,  basal  two-thirds  of  first  and  basal  half  of  sec- 
ond joint  of  hind  legs.     Halteres  yellow,  stalk  dusky  at  base. 

Frons  gloss}r  black,  sides  divergent,  about  one-third  wider  at  vertex 
than  above  antennae,  surface  hairs  strong,  upright,  black,  present 
only  on  lateral  margins,  especially  toward  vertex,  absent  from 
center;  face  distinctly  longer  than  broad  (1J:1),  grayish  pollinose, 
almost  bare  on  center,  with  long  hairs  on  lateral  and  lower  margins : 
antenna?  brown,  the  basal  two  joints  and  base  of  third  generally 
paler;  second  and  third  joints  elongated,  subequal,  as  long  as  4+5; 
pilosity  short,  thick,  pale;  palpi  black-brown,  black  haired;  post- 
ocular  cilia  black.  Mesonotum  with  very  slight  pale  pollinosity; 
pilosity  black  or  black-brown,  close-lying,  regular,  in  the  depression 
on  posterior  fourth  the  hairs  much  longer  and  upright;  pronotum 
with  numerous  black  hairs,  episternum  immediately  below  it  with 
pale  hairs;  all  the  lower  parts  of  pleura?  with  silky  pollinosity; 
pleural  tuft  brown-black,  confined  to  upper  fourth ;  scutelluni  opaque 
black,  the  upright  hairs  black,  no  pale  hairs  present.  Abdominal 
basal  scale  varying  in  color  from  pale  yellowish  to  opaque  black,  the 
long  hairs  pale  brownish  yellow ;  membrane  beneath  scale  generally 
yellow;  some  specimens  have  the  abdomen  inclining  to  brown;  seg- 
ments almost  bare  except  laterally  and  apically  where  there  are 
numerous  brown  hairs.  Legs  with  close-lying  pale  pilosity  and  dis- 
tinct, longer,  upright,  black  hairs  on  the  dorsal  surfaces  of  femora, 
tibia?,  and  tarsi;  the  usual  paired  apical  hairs  on  first  and  third  fore 
tarsal  joints  present  (PL  V,  fig.  11)  ;  hind  tibia1  at  apices  and  basal 
three-fourths  of  first  tarsal  joint  of  hind  legs  with  short,  stiff,  upright, 
golden  pile;  claws  with  tooth  (see  PI.  II,  fig.  8)  ;  wings  clear,  thick 
reins  brownish,  cross-vein  at  two-fifths  from  apex  of  subcosta. 

Length,  2  2.5  nun. 

Type.     Cat.  No.  1.V109,  U.  S.  National  Museum. 


SIMULIUM.  37 

Type  locality,  Red  Hill,  Moultonburgh,  N.  IT.,  August  5  (II.  G. 
Dyar).  There  are  specimens  from  Skyland,  Page  County,  Va.,  July 
15,  1912  (H.  G.  Dyar),  and  White  Mountains,  N.  II.  (Morrison). 

The  male  and  the  early  stages  are  unknown. 

Simulium  arcticum,  new  species. 

Female. — Black;  frons  shining,  very  slightly  dusted  with  white, 
face  thickly  white  dusted,  antennae  with  two  basal  joints  yellowish. 
Scutum  with  two  large  and  generally  distinct  white  pollinose  spots 
on  anterior  angles  of  scutum,  the  latter  slightly  shining;  pre- 
scutum  brownish;  scutellum  concolorous  with  scutum;  pleurae  sub- 
opaque,  distinctly  white-dusted,  especially  on  lower  portions.  Abdo- 
men black,  opaque  on  basal  four  segments,  shining  on  apical  four.  In 
some  specimens  distinctly  gray-dusted  laterally  and  posteriorly  on 
basal  five  segments.  Legs  yellow,  black  as  follows:  Femora  except 
bases,  tibiae  at  apices  and  tarsi  of  fore  legs;  coxa3,  femora  except 
bases,  apical  third  of  tibia?,  and  apices  of  first  tarsal  joint  of  mid  and 
hind  legs;  last  four  joints  of  mid  tarsi,  except  extreme  base  of  second; 
last  four  joints  of  hind  tarsi  except  basal  half  of  second.  Wings 
clear,  thick  veins  brownish.  Halteres  yellow,  brownish  at  base  of 
stalk. 

Frons  with  sides  very  slightly  divergent,  unusually  broad  at  anten- 
nae above,  occupying  about  one-fourth  the  wTidth  of  head,  at  vertex 
about  one-third  as  wTide  as  head,  surface  hairs  only  on  lateral  mar- 
gins; besides  the  scale-like  hairs  there  are  also  present  some  black, 
upright  hairs;  face  as  broad  as  frons  at  vertex,  and  about  one-third 
longer  than  broad,  surface  hairs  whitish,  absent  from  upper  third, 
antennal  pilosity  pale;  palpi  black,  hairs  black-brown;  postocular, 
cilia  pale,  with  a  few  intermixed  black  hairs  on  lower  portions. 
Scutum  covered  with  close-lying  whitish  or  yellowish  pilosity 
which  is  regularly  arranged  and  rather  long;  prescutellar  depression 
of  scutum  with  numerous  long,  upright,  black  hairs;  pleural  tuft 
pale;  scutellum  with  pale  scale-like  pilosity  and  numerous  long, 
upright,  black  hairs.  Abdominal  basal  scale  paler  than  rest  of  abdo- 
men, the  fringe  long  and  pale,  surface  hairs  on  apical  segments  pale 
and  on  lateral  margins  a  number  of  long  black  hairs.  Legs  with 
rather  long,  close-lying,  pale  pilosity  and  numerous  long,  upright, 
black  dorsal  hairs,  those  on  apices  of  first  and  third  fore  tarsal  joints 
not  conspicuous;  claws  with  subbasal  tooth  (see  PI.  II,  fig.  4).  AVing 
venation  as  in  parnassum. 

Length,  3^  mm. 

Type.— Cut.  No.  15410,  U.  S.  National  Museum. 

Type  locality,  Kaslo,  British  Columbia  (H.  G.  Dyar).  Also  from 
London  Hill  Mine,  Bear  Lake,  British  Columbia  (R.  P.  Currie). 

The  male  and  the  early  stages  are  unknown. 


38  AMERICAN   BLACK   FLIES   OR  BUFFALO   GNATS. 

Simulium  bracteatum  Coquillett. 

Female. — Opaque  black  or  brown-black;  basal  two  joints  of  an- 
tennas yellow,  palpi  black-brown.  Prescutum  and  margin  of  scutum 
bordering  on  it  yellowish,  pleurae  brown,  yellowish  posteriorly. 
darker  on  lower  central  portions,  scutellum  and  postscutum  black- 
brown.  Abdomen  opaque  black-brown.  Legs  yellow,  darkened  on 
apices  of  all  femora  and  tibiae,  entire  fore  and  mid  tarsi  except  ex- 
treme base  of  latter,  and  apices  of  first  and  second  and  all  remaining 
joints  of  hind  tarsi.  Wings  clear,  thick  veins  yellowish  brown. 
Halteres  pale  yellow,  darkened  at  base  of  stalk. 

Frons  rather  narrow,  sides  divergent,  less  than  one-third  the  width 
of  head  at  upper  angle  of  eyes,  and  more  than  one-half  as  wide  at 
lower  angle  as  at  upper,  surface  covered  with  close-lying,  thickly 
placed,  brassy  yellow,  scalelike  pilosity;  face  paler  in  color  than 
frons  and  equal  to  it  in  length,  distinctly  longer  than  broad,  pilosity 
rather  paler  and  looser  than  that  of  frons,  antennal  pilosity  pale; 
hairs  on  palpi  brownish.  Scutum  unstriped,  pilosity  very  close, 
rather  scale-like,  brassy  yellow  in  color;  pleural  tuft  pale  yellow; 
scutellum  with  close-lying  yellow  pilosity  and  long,  upright  yellow 
hairs ;  postscutum  with  yellow  pilosity.  Abdomen  with  close  pilosity, 
on  all  segments,  of  a  similar  nature  to  that  on  mesonotum,  apical 
segment  with  longish  hairs.  Legs  with  close-lying  yellow  pilosity 
on  the  yellow  parts,  which  is  longer  on  the  dorsal  surfaces,  and  brown 
hairs  and  pilosity  on  the  dark  portions ;  claws  as  in  Plate  II,  figure  14 
(Prosimulium  pecuarum)  ;  hind  tarsi  with  basal  joint  produced  at 
apex  and  second  with  scale  and  basal  constriction. 

Length,  2.5-3  mm. 

Redescribed  from  type  specimens,  Cambridge,  Mass.,  May  31,  1869. 
There  is  also  one  female  in  the  collection  from  Plummers  Island. 
Md.,  April  19,  1903  (H.  S.  Barber),  one  female  from  Franconia, 
N.  II.  (Mrs.  A.  T.  Slosson),  and  one  female  from  Los  Angeles,  Cal. 
(collection  Coquillett). 

There  are  several  males  and  one  female  in  the  collection  of  the 
Illinois  State  Laboratory  of  Natural  History  from  Algonquin,  111. 
(Nason). 

Male. — Opaque  black.  Head  in  type  broken  off.  Scutum  with 
indistinct  anterior  whitish  dusting,  prescutum  yellowish,  pilosity 
brassy  yellow,  rather  more  hairlike  than  in  female  and  distinctly 
longer,  lateral  margins  of  scutum  brownish,  pleural  tuft  pale  yellow, 
scutellar  pilosity  and  hairs  long,  yellow,  postscutum  bare.  Abdomi- 
nal basal  fringe  long,  yellow,  all  segments  with  long  yellow  pilosity, 
dial  on  basal  four  segments  laterally  very  thickly  placed  and  adher- 
ing closely  to  surface,  apical  four  segments  with  pilosity  much 
shorter  and  sparse.     Legs  blown,  apically  the  joints  slightly  dark- 


SIMULIUM.  39 

ened,  pilosity  yellow,  on  fore  tibia;  dorsal  surfaces  silvery,  dorsal 
surfaces  of  all  joints  with  longer,  upright,  pale  hairs,  fore  tarsi  no1 
distinctly  thickened,  hind  tarsi  with  basal  joint  slightly  thinner 
than  tibiae  and  produced  at  apex  posteriorly,  second  joint  with  basal 
scale  and  excision;  claws  trifid.  Wings  as  in  female.  Ilalteres 
brown. 

Length,  3  mm. 

Locality:  Los  Angeles,  Cal.  (collection  Coquillett). 

In  the  original  description  of  the  male  of  this  species  there  are  so 
many  details  left  out  that  I  have  considered  it  better  to  redescribe  it. 

I  have  not  seen  the  larva  or  pupa  of  this  species,  but  Mr.  E.  H. 
Strickland  has  reared  it  in  Massachusetts.  His  description  of  it  agrees 
in  both  stages  very  well  with  that  given  by  Hart  for  S.  johannseni. 

The  larva  differs  from  that  of  other  species  of  Simidium,  except 
johannseni,  in  having  the  outer  tooth  on  each  side  rounded  and  with 
an  apical  pointed  process.  The  lateral  setae  number  two  on  each  side. 
The  pupa  has  only  four  respiratory  filaments,  and  should  be  readily 
recognizable  from  any  other  North  American  species  except  johann- 
seni  by  that  character  alone. 

I  have  not  seen  the  specimens  reared  by  Strickland  and  have  to 
accept  his  published  authority  for  the  identification. 

Simulium  exiguum  Roubaud. 

Female. — Black,  subshining.  Frons  very  slightly  dusted,  face  dis- 
tinctly whitish  pollinose,  antennae  yellow,  basal  joint  and  apical 
joints  slightly  browned,  palpi  yellow,  brown  at  apex.  Scutum  un- 
dusted,  pleurae  with  distinct  pearlaceous  pollinosit}7,  postscutum 
whitish  pollinose.  Abdomen  black,  segment  below  basal  scale  entirely 
covered  with  pearlaceous  pollinosity,  next  segment  opaque,  the  re- 
mainder glossy  on  disk,  with  slight  indications  of  whitish  pollinosity 
on  lateral  margins.  Legs  yellow,  blackened  on  mid  and  hind  coxae, 
fore  tarsi  from  apex  of  first  joint  to  tip,  last  joint  of  mid  tarsi,  mid- 
dle of  femora,  apices  of  tibiae,  ventral  surfaces  of  first  joint  at  apex 
and  last  joint  of  tarsi  of  hind  legs.  Wings  clear,  thick  veins  yellow. 
Halteres  yellow. 

Frons  with  sides  very  slightly  divergent  posteriorly,  occupying  at 
upper  angle  of  eyes  less  than  one-third  the  head  width;  face  much 
more  elongate  than  usual,  nearly  twice  as  long  as  broad,  as  broad 
as  frons  at  lower  angle;  both  face  and  frons  with  extremely  weak 
surface  hairs;  occiput  with  pearlaceous  pollinosity;  postocular  cilia 
weak,  dark.  Scutum  with  iridescent,  golden  yellow,  rather  troad, 
scalelike  pilosity  which  is  arranged  in. irregular  groups;  pleural  tuft 
wTeak,  brown;  scutellum  with  similar  pilosity  to  scutum  and  some 
long,  upright,  brown  hairs.     Abdominal  basal  fringe  short,  sparse, 


40  AMERICAN   BLACK   FLIES   OE  BUFFALO   GNATS. 

brown,  apical  segments  with  sparse,  dark  surface  hairs.  Legs  with 
pale  yellow  hairlike  pilosity  and  a  few  longer,  upright,  brown  dorsal 
hairs,  the  normal  paired  apical  hairs  present  on  first  and  third  joints 
of  fore  tarsi;  fore  tarsi  slender,  hind  tarsi  with  apical  four  joints 
three-fourths  as  long  as  basal  joint;  tarsal  claws  simple.  Hairs  at 
base  of  first  vein  black,  surface  hairs  on  veins  black,  anal  wing  fringe 
whitish. 

Length,  1.5-2  mm. 

Four  females,  Sarare,  Venezuela  (T.  Gray),  examined  by  Eou- 
baud;  four  females  taken  on  board  ship  4  miles  off  Livingston, 
Guatemala,  March  20,  1906,  one  female,  Cacao,  Trece  Aguas,  Guate- 
mala, and  one  female,  same  locality,  April  12,  1906,  labeled  "  Biting 
man"  (Schwarz  and  Barber). 

This  very  prettily  marked  species  can  not  be  confounded  with  any 
other  which  I  have  examined. 

The  male  and  the  early  stages  are  unknown. 

Simulium  clavipes,  new  species. 

Female. — Black,  subopaque.  Frons  and  face  distinctly  white- 
dusted  ;  antennas  brown,  the  basal  two  and  base  of  third  joints  yellow ; 
palpi  brown,  pale  at  base.  Scutum  in  some  specimens  with  faint 
indications  of  a  central  stripe  and  anteriorly  with  slight  wrhitish  pol- 
linosity ;  scutum  shining  posteriorly,  prescutum  yellow ;  pleura?  brown, 
darker  anteriorly  and  with  whitish  pollinosity;  scutellum  and  post- 
scutum  brown,  the  latter  with  white  pollinosity.  Abdomen  black, 
opaque  on  basal  four  segments,  glossy  on  apical  four.  Legs  }Tellow, 
black  on  mid  and  hind  coxa?,  apices  of  all  tibia?,  and  entire  tarsi,  ex- 
cept base  of  first  joint  of  mid  tarsi,  and  greater  part  of  first  and  basal 
half  of  second  joint  of  hind  tarsi.  ^Vings  clear,  thick  veins  brown. 
Halteres  yellow. 

Frons  slightly  divergent-sided,  three-fourths  as  wide  at  lower  angle 
as  at  upper,  surface  hairs  brown,  sparse,  upright;  face  subquadrate, 
as  broad  as  frons  at  lower  angles  and  similarly  haired;  hairs  on  palpi 
brown;  postocular  cilia  brownish  black,  strong.  Scutum  with  golden 
yellow  pilosity  which  is  rather  loose  and  irregularly  arranged,  though 
not  grouped;  besides  the  pile  there  are  regularly  arranged  brown 
hairs  over  the  entire  disk,  which  are  much  more  distinct  on  margins 
and  especially  posteriorly;  pleural  tuft  brown,  sparse;  scutellum  with 
yellow  decumbent  pilosity  and  long,  upright  brown  hairs.  Basal 
fringe  of  abdomen  yellow7,  surface  hairs  on  apical  segments  pale 
brown,  sparse.  Legs  strong,  clothed  with  yellow  pilosity,  and  with 
numerous  longer,  upright,  dorsal  brown  hairs  which  are  more  notice- 
able <>i)  tibia  mid  tarsi;  fore  tarsi  broad,  first  and  third  joints  with 
paired  apical  hairs;  hind  tarsi  with  basal  joint  narrower  than  tibia?, 


SIMULIUM.  41 

apical  four  joints  about  two-thirds  as  long  as  basal  joint;  tarsal  claws 
as  shown  in  Plate  II,  figure  5. 

Length,  3^  mm. 

Type.— Cat.  No.  15411,  U.  S.  National  Museum. 

Locality. — Guadeloupe,  West  Indies,  4,000-foot  level,  July  (August 
Busck). 

It  is  improbable  that  this  is  the  species  described  as  S.  tarsale  by 
Williston,  the  description  of  which  is  given  on  pages  4G-47.  The  size, 
color,  and  locality  are  quite  enough  to  justify  me  in  separating  it, 
even  if  the  vestiture  were  overlooked  by  Williston  in  describing  his 
species  in  so  far  as  the  presence  of  the  upright  brown  hairs  on  scutum 
are  concerned. 

The  early  stages  of  this  species  are  unknown,  and  there  are  no  males 
among  the  material  in  the  collection. 

Simulium  jenningsi,  new  species. 

Female. — Black,  shining.  Frons  and  face  shining,  the  former 
slightly,  the  latter  distinctly  white-dusted;  antennae  brown,  basal 
three  joints  paler,  yellowish;  palpi  brown.  Scutum  shining  black, 
with  distinct  pearlaceous  pollinosity,  which  does  not  form 
spots,  but  is  most  distinct  near  margins  of  prescutum  and  tapers 
off  toward  center  of  disk;  pleurae  glossy  black,  distinctly  whitish 
pollinose  on  lower  central  portions ;  scutellum  velvety  opaque  black ; 
postscutum  whitish  pollinose.  Abdomen  with  basal  four  segments 
opaque  black,  apical  four  glossy  black.  Legs  black,  yellow  as 
follows:  Coxa?,  bases  of  femora  narrowly,  and  at  bases  of  tibiae 
broadly  of  fore  legs;  trochanters,  bases  of  femora,  bases  of  tibiae 
broadly,  and  basal  three  tarsal  joints  except  apices,  on  mid  and  hind 
legs.  All  tibiae  silvered  on  basal  half  of  dorsal  surface.  Wings 
clear,  basal  portions  of  veins  brown,  thick  veins  yellow.  Halteres 
with  lemon-yellow  knob  and  brown  stalk. 

Frons  broad,  distinctly  more  than  one-third  as  wide  at  upper 
angle  of  eyes  as  head  width,  slightly  divergent-sided,  hairs  sparse, 
pale,  confined  to  lateral  posterior  margins;  face  slightly  narrower 
than  frons  at  widest  part,  about  one-third  longer  than  wide  and  as 
long  as  frons,  surface  hairs  pale,  sparse,  though  more  numerous  than 
on  frons ;  hairs  on  palpi  pale ;  postocular  cilia  brown.  Scutum  with 
yellow,  sparse,  rather  widely  placed,  regular  hairlike  pilosity,  no 
long  posterior  hairs  on  scutum ;  pleural  tuft  sparse,  short,  brownish ; 
postspiracular  area  bare ;  scutellum  with  upright  brown  hairs.  Basal 
abdominal  fringe  brownish  yellow,  surface  hairs  on  apical  four  seg- 
ments sparse,  yellowish.  Pilosity  on  legs  yellow,  except  on  the  basal 
half  of  dorsal  surfaces  of  tibiae  where  it  is  white,  giving  the  silvery 
appearance  which  is  so  noticeable  in  this  and  allied  species;  the 


42  AMERICAN   BLACK   FLIES   OR  BUFFALO   GNATS. 

usual  longer  dorsal  hairs  weak ;  fore  tarsi  dilated,  as  broad  as  tibiae, 
first  and  third  joints  with  paired  apical  hairs;  hind  tarsi  of  similar 
form  to  venustum  Say;  claws  simple.  Wing  venation  normal,  sur- 
face hairs  and  short  bristles  brownish  yellow.  Sometimes  the  pilosity 
on  scutum  is  brownish  or  almost  black,  but  this  is  exceptional. 

Length,  1-1.5  mm. 

Type.— Cat.  No.  15412,  U.  S.  National  Museum. 

Male. — Similar  in  size  and  color  to  the  female  except  that  the 
mesonotum  is  velvety  opaque  black;  the  scutum  has  two  silvery  or 
pearlaceous  stripes  running  from  the  margin  of  the  prescutum  back- 
ward and  inward  to  almost  middle  of  disk ;  the  lateral  and  posterior 
margins  of  scutum  are  distinctly  silvery  pollinose;  the  pilosity  is 
darker  and  longer,  being  more  hairlike  than  in  female.  The  abdomen 
is  not  distinctly  shining  on  apical  segments,  and  the  hairs  are  longer 
and  darker.  The  legs  are  similar  in  color  to  those  of  the  female, 
but  the  tibiae  are  only  pale  at  extreme  base;  they  are  longer  haired 
and  the  claws  are  trifid  (see  PL  V,  fig.  12).  The  eyes  are  of  similar 
formation  to  those  of  the  males  of  venustum. 

Allotype. — Cat  No.  15412,  U.  S.  National  Museum. 

There  are  reared  specimens  in  the  collection  bearing  the  number 
4425.  These  emerged  from  pupae  sent  to  the  Bureau  of  Entomology 
in  May,  1889,  from  Friersons  Mill,  La. 

An  examination  of  the  pupa  discloses  the  fact  that  this  is  in  all 
probability  the  species  described  in  the  larval  and  pupal  stages  by 
Johannsen  in  the  paper  already  mentioned.  I  give  a  copy  of  the 
characters  mentioned  by  Johannsen  for  his  variety  a  of  ve?iustum, 
which  he  was  unable  to  separate  from  the  type  except  by  size  in  the 
imago. 

A  number  of  specimens  bred  from  larvae  and  pupa?  taken  from  Fall  Creek, 
Ithaca,  New  York,  differs  in  the  adult  stage  from  venustum  as  described  above 
in  being  uniformly  smaller  (length  1.5  mm.)  ;  having  the  base  of  wing  brownish 
and  not  yellow,  and  in  having  the  last  four  abdominal  segments  of  the  female 
a  shining  black  instead  of  brown.  The  larva  differs  as  follows:  in  size  averag- 
ing less  than  two-thirds  that  of  venustum,  labruin  [labium]  with  its  toothed 
edge  wider  in  proportion  to  its  size  than  in  venustum,  its  teeth  more  nearly  of 
a  size,  the  ventral  setae  three  in  each  row,  plus  a  very  small  one.  The  pupa 
differs  in  having  10  respiratory  filaments  in  each  tuft,  the  hooks  on  segment  2 
more  distinct,  and  the  tubercules  on  the  anal  segments  apparently  wanting. 

This  species  stood  in  the  collection  as  S.  venustum  Say,  and  both 
sexes  are  represented  among  the  specimens  reared  from  the  pupa1 
from  Friersons  Mill.  There  are  specimens  in  the  collection  from 
Spring  Hill,  Fairfax  County,  Va.;  Chevy  Chase,  Md.,  July  4,  1907; 
Cabin  John,  Md.,  May  10,  1001);  Beltsville,  Md.,  September  21,  1911; 
and  Washington,  D.  C,  July  3,  1910  (F.  Knab)  ;  Minnesota  (Lug- 
ger) ;  Inman.  Spartanburg,  and  Gramlin,  S.  C. ;  and  Flat  Rock, 
N.  C.    (Jennings  and  King)  ;  and  Biscayne  Bay,  Fla.    (Mrs.  A.  T. 


SIMULIUM.  43 

Slosson).  There  are  several  specimens  of  both  sexes  in  the  collection 
of  the  Illinois  State  Laboratory  of  Natural  History  from  Algonquin, 
111.  (Nason). 

This  species  attacks  horses  and  is  a  persistent  biter  in  South 
Carolina,  according  to  the  observations  of  Messrs.  Jennings  and 
King.  Their  data  for  the  adults  of  the  species  on  which  observa- 
tions were  made  are  as  follows: 

Lot  382.  Gramlin,  S.  C.,  August  19,  1012.  Two  dozen  Simulium  adults  col- 
lected in  ears  of  a  horse.  Owner  lives  some  distance  out  in  the  country.  He 
gave  a  history  of  being  bitten  by  these  flies.  His  team  had  come  from  the 
farm  a  couple  of  hours  before.     No  larvae  or  pupae. 

Lot  383.  Gramlin  S.  C,  August  19,  1912.  Simulium  adults  from  ears  of  a 
horse,  collected  as  horse  was  passing  along  the  road.  No  larvae  or  pupae. 
Driver  gave  no  history  of  being  bitten  by  the  flies. 

Lot  214.  Flat  Rock,  N.  C,  June  5,  1912.  Simulium  adults  taken  while  attack- 
ing a  horse.  Were  entering  ears  and  biting  on  face,  neck,  and  shoulders  also. 
(No  larval  or  pupal  material.) 

Lot  220.  Flat  Rock,  N.  C,  June  4,  1912.  Simulium  adults  taken  while  attack- 
ing a  horse.  After  removal  of  horse  they  continued  to  dance  in  small  swarms 
about  the  same  spot.  Situation  shaded  by  tall  trees.  (No  larval  or  pupal 
material.) 

The  dates  of  occurrence  of  this  species  range  from  May  G  on  the 
Louisiana  specimens  to  September  21  on  those  from  Beltsville,  Md., 
and  from  the  continuity  it  is  evident  that  there  must  be  many  broods 
or  an  unintermittent  reproduction  during  the  entire  summer. 

The  figures  given  on  page  16  of  Bulletin  159  of  the  Kentucky  Agri- 
cultural Experiment  Station  by  Garman  are  evidently  details  of  the 
larva  of  this  species,  though  the  pupa  figured  on  page  15  belongs 
either  to  meridionale  or  venustum. 

Simulium  venustum   Say. 

Female. — Black;  frons  glossy  black,  with  very  little  dusting,  face 
black,  distinctly  white  dusted,  antennae  with  basal  three  joints  yel- 
lowish, palpi  black.  Scutum  shining  black,  with  slight  whitish 
pollinosity,  especially  anteriorly  and  on  sides,  prescutum  yellowish 
or  brownish,  pleurae  black,  white  dusted,  scutellum  opaque  black. 
Abdominal  basal  scale  opaque  black  or  brown,  basal  four  segments 
velvety  black,  apical  four  glossy  black.  Legs  yellowish,  black  as 
follows :  Mid  and  hind  coxa? ;  femora  more  or  less  at  apices ;  tibiae  or 
apical  halves ;  entire  fore  tarsi ;  apices  of  basal,  most  of  second,  and  all 
last  three  joints  of  mid  and  hind  tarsi.  All  tibiae  silvered  on  dorsal 
surfaces.  Wings  clear,  basal  portion  and  thick  veins  brown.  Hal- 
teres  whitish  yellow. 

Frons  very  sparsely  haired  on  sides  only,  about  one-half  as  wide 
above  antennae  as  at  vertex;  face  nearly  as  broad  as  frons  at  vertex 
and  very  slightly  longer  than  broad  measured  from  highest  point 
in  center  to  mouth  margin,  the  surface  hairs  black;  antennal  pilosity 


44  AMERICAN  BLACK   FLIES   OR  BUFFALO   GNATS. 

white;  hairs  on  palpi  brown;  postocular  cilia  pale,  with  a  consider- 
able admixture  of  black  hairs.  Scutum  with  a  slight  indication 
of  a  central  black  stripe  in  front;  pilosity  very  close  and  short, 
yellow,  the  normal  long  upright  hairs  on  posterior  depression  incon- 
spicuous; plural  tuft  brown;  post-spiracular  area  pale  haired;  scu- 
tellum  with  yellow  pile  and  long  upright  black  hairs.  Abdominal 
basal  fringe  pale  brownish  yellow ;  segment  beneath  scale  silvered, 
yellowish  except  at  apex;  apical  segments  with  numerous  short 
brown  hairs  which  are  longer  on  lateral  margins.  Fore  tarsi  flat- 
tened, the  normal  paired  apical  hairs  present,  surface  pilosity  pale  and 
short,  the  upright  hairs  not  very  conspicuous ;  claws  simple.  Wings 
with  brown  hairs  at  base  of  first  vein. 

Length,  2-2.5  mm. 

Male. — Opaque  black.  Antenna?  black,  the  basal  two  joints  and 
base  of  third  joint  yellowish.  Scutum  velvety  black,  posterior  and 
lateral  margins  with  silvery  pollinose  dusting,  disk  with  an  oblique 
backward  and  inwardly  directed  white  stripe  which  stops  short  of 
middle,  pilosity  }^ellowish  brown.  Abdomen  with  basal  fringe 
brownish;  segments  opaque  black;  first  segment,  below  scale,  pear- 
laceous  pollinose ;  apical  ventral  segments  similarly  pollinose.  Legs 
black;  anterior  tibiae  with  basal  half  yellow,  and  whitish  pollinose 
on  the  dorsal  surface,  hind  and  mid  tibia?  only  yellow  at  bases  (Plate 
V,  fig.  1)  ;  fore  coxa?,  base  of  basal  mid  tarsal  joints,  and  bases  of 
basal  and  second  hind  tarsal  joints  yellow;  claws  trifid.  Otherwise 
as  in  the  female,  except  in  the  confluent  eyes. 

Larva. — Yellow,  with  dark  cross-bands  on  the  segments.  Fans 
with  about  60  rays.  Labium  with  middle  tooth  longest,  the  outer 
one  slightly  shorter,  and  the  three  intervening  teeth  considerably 
smaller. 

J'upa. — Respiratory  filaments  six  in  number  (PI.  IV,  fig.  3).  Co- 
coon shaped  like  a  small  conical  pocket  and  attached  to  leaves  or 
stems  of  plants  growing  in  the  water.  The  cocoons  are  very  closely 
placed  and  almost  identical  with  those  of  vittatum  and  je7iningsi. 

This  is  one  of  the  commonest  species  in  the  genus.  There  lias 
been  much  confusion  regarding  the  identity  of  this  and  closely  allied 
species,  and  possibly  there  is  more  than  one  species  among  those  I 
have  before  me.  An  exhaustive  study  of  the  early  stages  may  settle 
this  question,  but  the  material  before  me  at  present  does  not  perm  it 
of  my  forming  a  definite  opinion  as  to  the  specific  distinctions  of  some 
of  the  specimens.  I  have  described  the  male  and  female  above  from 
the  same  lot  of  reared  specimens,  the  larva?  and  pupa)  of  which  agree 
with  those  described  by  Johannsen.  The  species  was  originally  de- 
scribed by  Say  from  Shippingsport,  Falls  of  the  Ohio. 

The  materia]  in  the  U.  S.  National  Museum  collection  is  from  the 
following  localities:  White  River,  Ontario,  and  Oxbow,  Saskatche- 


SIMULIUM.  45 

wan,  Canada,  June,  1907  (F.  Knab)  ;  St.  Louis,  Mo.,  May  6,  1904 
(W.  Y.  Warner);  Congaree,  S.  C,  March-April,  1912;  Abbeville, 
S.  C.,  April,  1912;  Greenwood,  S.  C,  April,  1912;  Columbia,  S.  C, 
April,  1912;  Tacapaw  Mills,  S.  C,  August  28,  1912;  Spartanburg, 
S.  C,  July  15,  1912  (reared)  ;  and  Greenville,  S.  C,  May,  1912 
("taken  ovipositing  in  stream")  (Jennings  and  King).  Specimens 
in  the  Illinois  State  Laboratory  of  Xatural  History  collection  are 
from  Algonquin  and  Havana,  111. 

The  figures  given  by  Garman1  are  evidently  those  of  the  larva  of 
jenningsi  and  not  venustum.  The  larva  and  pupa  described  by  Jo- 
hannsen  in  his  paper  as  venustum  var.  a  are  those  of  jenningsi. 

Simulium  piscicidium  Riley. 

Female. — Black,  subopaque.  Frons  and  face  with  distinct  white 
pollinosity ;  antennae  brown,  basal  two  joints  yellowTish ;  palpi  brown. 
Scutum  with  white  pollinosity  on  anterior  lateral  angles  posterior 
to  prescutum;  prescutum  sometimes  brownish  or  yellowish;  pleurae 
whitish  pollinose ;  scutellum  brown  or  yellowish ;  postscutum  whitish 
pollinose.  Abdomen  with  basal  four  segments  opaque,  the  apical 
four  shining,  but  not  glossy;  lateral  posterior  margins  of  first  four 
segments  white  pollinose.  Legs  yellow,  blackened  as  follows:  Mid 
and  hind  coxae ;  apices  of  femora  slightly ;  apices  of  tibiae  of  all  legs 
distinctly;  fore  tarsi  entirely;  entire  mid  tarsi  except  base  of  first 
joint;  hind  tarsi  except  basal  two-thirds  of  first  and  base  of  second 
joint.  Wings  clear,  thick  veins  yellow,  venation  normal.  Halteres 
yellow,  base  of  pedicel  darkened. 

Frons  divergent-sided,  one-third  as  wide  at  upper  angle  of  eyes 
as  head  width,  two-thirds  as  wide  at  lower  angle  as  at  upper,  sur- 
face hairs  sparse,  white;  face  as  long  as  frons,  about  one-third  longer 
than  broad,  haired  as  frons;  hairs  on  palpi  pale;  postocular  cilia 
mostly  pale,  with  a  few  longer,  black  hairs  intermixed.  Scutum  with 
short,  hairlike,  white,  regular  pilosity,  the  hairs  on  posterior  fourth 
not  conspicuous;  pleural  tuft  whitish;  postspiracular  area  sparsely 
pale  haired;  scutellum  with  long,  upright,  brownish  hairs  and  close- 
lying  pale  pilosity.  Abdominal  basal  fringe  yellow;  surface  hairs 
on  segment  short,  pale,  those  at  apex  longer  and  dark.  Legs  with 
pale  pilosity  and  longer,  upright,  dorsal,  brownish  hairs;  fore  tarsi 
dilated,  the  apical  paired  hairs  present  on  joints  1  and  3;  claws  as  in 
venustum.  Hairs  and  short  bristles  on  vein  surfaces  of  wings 
brownish. 

Length,  3-4  mm. 

Male. — Deep  black.  Face  silvery  pollinose ;  antennae  entirely  black ; 
palpi  black.  Scutum,  viewed  from  in  front,  with  two  black,  sub- 
triangular  marks  on  the  anterior  margin,  the  space  between  them 
with  a  dull  brown  stripe  which  shows  conspicuously  against  the  white 

1  Bui.  159,  Ky.  Agr.  Exp.  Sta.,  1912,  p.  16. 


46  AMERICAN   BLACK   FLIES   OR  BUFFALO   GNATS. 

pollinose  disk ;  on  each  side  of  this  central  stripe  there  is  a  black  stripe 
which  is  slightly  dilated  anteriorly,  does  not  extend  either  to  anterior 
or  posterior  margin,  and  becomes  diffuse  brownish  on  margins; 
viewed  from  behind  the  two  small,  sub  triangular  spots  are  bright 
silvery;  the  whole  disk,  except  on  the  aforementioned  black  stripes, 
white  pollinose.  Scutellum  slightly  white  dusted ;  postscutum  silvery. 
Abdomen  with  the  segment  below  basal  scale  and  sides  of  5  and  6 
more  or  less  broadly  silvered.  Legs  black ;  tibiae  white  on  dorsal  sur- 
face: bases  of  all  tibiae  yellow,  the  hind  pair  very  noticeably  yellow 
on  basal  half;  base  of  first  joint  of  mid  tarsus,  all  except  apex  of 
first  joint  of  hind  tarsus,  and  base  of  second  of  the  latter  yellow. 

The  pilosity  of  the  scutum  is  hairlike,  pale  yellowish,  longer  pos- 
teriorly ;  there  are  no  black  hairs  present  either  on  the  disk  or  on  the 
scutellum.  Basal  abdominal  fringe  brown.  Legs  rather  slender; 
fore  tarsus  slender,  the  apical  hairs  not  noticeable. 

I  have  not  seen  the  larva  of  this  species,  but  it  is  described  by 
Johannsen  as  having  the  teeth  on  the  labium  more  nearly  of  an 
equal  size  than  in  venustum*,  and  the  ventral  surface  of  same  with 
seven  setae  in  each  lateral  row.  The  pupa  has  the  respiratory  organs 
with  eight  branches  (PI.  VI,  fig.  5).  The  cocoon  is  similar  to  that  of 
venustum. 

Piscicidium  was  originally  described  from  Mumford,  X.  Y.,  by 
Riley,  and  was  at  one  time  considered  to  be,  in  the  larval  stage, 
responsible  for  the  death  of  young  trout.  This  has  been  proved 
to  be  a  mistake.  Two  specimens  of  the  original  series  only,  marked 
type,  are  in  the  collection.  There  are  also  several  specimens  in 
the  collection  from  Pine  River,  Lake  Superior,  September  7,  189G 
(Hubbard)  ;  Kukak  Bay,  Alaska  (T.  Kincaid) ;  and  Lake  View, 
Miss.,  April  10,  1886. 

Coquillett  considered  this  species  as  synonymous  with  venustum 
Say,  and  Johannsen,  though  possessing  larva?  and  pupae,  was  unable 
to  separate  it  from  Say's  species  in  the  perfect  state.  There  is  not 
the  slightest  doubt  that  it  is  a  distinct  species,  possessing  char- 
acters in  all  the  stages  which  easily  separate  it  from  venustum. 

I  have  drawn  up  the  description  of  the  male  from  a  specimen  of 
m an  strides  Hart,  which  is,  I  am  convinced,  synonymous  with  piscici- 
dium. The  specimens  in  the  collection  of  the  Illinois  State  Labora- 
tory of  Natural  History  are  from  Algonquin,  111.,  May,  July,  August, 
and  October  (Nason). 

This  is  in  all  probability  the  species  recorded  as  being  such  a 
persistent  biter  in  the  Lake  Superior  district. 

Simulium    tarsale    Williston. 
The  following  is  a  copy  of  Willistoirs  original  description: 
9.  Abdomen  black,  tin*  proximal  segments  opaque,  the  distal  four  segments 
Bhining.     Length  2  nun. 


SIMULIUM.  47 

Front  and  face  black,  with  a  Light  gray  reflection.  Antennae  yellow;  the 
distal  joints  somewhat  brownish.  Mesonotum  deep  black;  In  front,  opaque 
with  a  silvery  shimmer,  and  with  sparse,  curly,  golden-yellow  tomentum;  be- 
hind, shining.  Pleurae  black,  whitish  pruinose.  Abdomen  black,  the  basal  seg- 
ments opaque,  the  distal  four  segments  somewhat  shining,  and  with  a  delicate 
whitish  pruinosity.  Legs  reddish-yellow;  tarsi  black,  except  that  the  proximal 
half  of  the  middle  and  hind  metatarsi  light  yellow;  first  and  third  joints  of 
the  front  pair  each  with  two  long  hairs;  second  and  third  joints  of  the  same 
pair  dilated,  the  fourth  and  fifth  very  small ;  hind  metatarsi  elongate  and  stout, 
the  following  two  joints  a  little  dilated,  the  fourth  and  fifth  small.  Wings 
hyaline,  veins  yellow. 

This  species  must  belong  to  the  group  which  is  represented  by 
venusturn  Say,  and  several  other  closely  allied  forms,  but  it  is  not 
possible  to  say  just  what  species  the  author  had  before  him  at  the 
time  he  wrote  his  description.  I  have  not  seen  any  species  from  St. 
Vincent,  which  is  the  type  locality  of  tarsale,  and  can  not  be  certain 
as  to  its  status.  It  is,  however,  highly  improbable  that  it  is  the 
pulchrum  which  Philippi  described  from  Chile,1  as  suggested  by 
Hunter. 

GROUP    D. 

Scutum  striped,  the  stripes  three  or  five  in  number  (or  one  central 
stripe,  griseum),  the  dorso-lateral  pair  curved,  dilated  at  anterior 
ends,  and  generally  with  the  dilated  portion  white-pollinose,  the 
central  stripe  generally  linear. 

TABLE    OF    SFECIES. 

1.  Scutum  with  pearlaceous  pollinose  stripes metallicum,  p.  48. 

Scutum  with  black  or  brown  stripes;   if  these  are  pollinose  they  are 

never  metallescent  or  pearlaceous 2 

2.  Claws  with  the  base  prolonged  thumblike 3 

Claws  with  the  base  dilated  or  slightly  tuberculate,   or  with  a  small 

subbasal  tooth  in  center  in  addition  to  the  tuberculate  base 5 

3.  Larger  species,  3-4  j$m. ;  abdomen  with  long  hairs  laterally,  and  the 

black  marks  showing  as  a  series  of  black  spots  on  the  sides. 

johannscni,  p.  65. 
Smaller   species,    2-3   mm. ;    abdomen   with   the   black   marks   forming 
fascia? 4 

4.  Outer  vittae  on  scutum  much  curved,  basal  scale  of  second  hind  tarsal 

joint  indistinct meridionale,  p.  40. 

Outer  vittse  slightly  curved,  basal  scale  distinct forbcsi,  p.  G3. 

5.  Claws  simple (> 

Claws  with  central  tooth G 

6.  Scutum  black,  thickly  white-dusted,  one  central  black  stripe  on  disk; 

abdomen  yellow,  with  black  dorso-central  spots griseum,  p.  52. 

Scutum  with  at  least  three  stripes,  not  thickly  white-dusted ;  abdomen 
never  yellow 7 

^Yufziihlung  cler  clulenischen  Dipteren,  1865,  p.  633. 


48  AMERICAN   BLACK   FLIES   OR   BUFFALO    GNATS. 

7.     Scutum    with    five    very    distiuct    brown    stripes   on   a     light    gray 

ground vittatum,  p.  53. 

Scutum  with  three  less  distinct  stripes,  ground  color  dark  gr&j-pictipes,  p.  55. 
S.     Legs  mostly  yellow virgatum,  p.  57. 

Legs  mostly  black hunteri,  p.  59. 

Simulium  metallicum  Bellardi. 

Female. — Black,  shining.  Frons  glossy,  only  slightly  pollinose: 
face  thickly  covered  with  pollinosity  which  is  slightly  pearlaceous 
in  color;  antennae  with  the  basal  two  joints  and  most  of  third  joint 
yellow.  Scutum  with  three  stripes,  the  central  one  narrow,  the  lat- 
eral ones  anteriorly  dilated  and  posteriorly  divergent,  then  curved 
inward  and  ending  at  about  last  third  of  scutum;  viewed  from  be- 
hind these  stripes  are  iridescent  or  pearlaceous  in  color;  from  in 
front  they  are  opaque  black,  and  the  remainder  of  scutum  is  pearla- 
ceous; prescutum  brownish;  pleurae  with  pearlaceous  dusting,  gloss}7 
black ;  scutellum  brownish  opaque ;  postscutum  with  pearlaceous  dust- 
ing. Abdomen  black,  opaque  on  basal  four  segments,  glossy  black  on 
apical  four,  side  of  first  segment  under  basal  scale  with  pearlaceous 
dusting,  next  three  with  narrow,  lateral,  whitish,  posterior  margins. 
Legs  black,  yellow  as  follows:  Coxae  at  apices,  trochanters,  and 
femora  of  fore  pair ;  trochanters,  bases  of  tibiae,  most  of  basal,  second, 
and  third  joints  of  tarsi  of  mid  pair;  trochanters,  bases  of  tibiae,  all 
but  apex  of  first,  and  basal  half  of  second  tarsal  joints  of  hind  pair. 
All  tibiae  silvery  white  dusted  on  dorsal  surfaces.  Halteres  bright 
yellow,  stalk  brown.  Wings  clear,  basal  veins  brown,  thick  veins 
yellow. 

Frons  slightly  divergent-sided,  less  than  one-third  as  wide  at  up- 
per angle  of  eyes  as  width  of  head,  surface  hairs  sparse,  brown ;  face 
nearly  as  long  as  frons  and  one  and  one-half  times  as  long  as  broad, 
surface  hairs  pale  brown ;  hairs  on  palpi  brownish ;  postocular  cilia 
brown.  Scutum  with  sparse,  yellow,  decumbent,  scale-like  pilosity 
which  is  longer  posteriorly ;  pleural  tuft  weak,  brown ;  scutellum  with 
long,  upright,  brown  hairs  on  hind  margin.  Abdominal  basal  fringe 
rather  short,  yellowish,  surface  hairs  on  abdomen  sparse,  brown. 
Legs  with  brownish-yellow  pilosity  and  scattered,  upright,  dorsal, 
brown  hairs;  fore  tarsi  dilated,  basal  joint  as  broad  as  tibia,  and 
like  the  third  furnished  with  the  apical  paired  hairs;  claws  as  shown 
on  Plate  II,  figure  17.  Thick  veins  of  wings  with  black-brown  sur- 
face hairs  and  short  bristles,  thin  veins  very  indistinct. 

Length,  2  mm. 

There  are  quite  a  number  of  specimens  in  the  collection  which  I 
consider  are  referable  to  this  species.  The  localities  are:  Trinidad. 
West  Indies  (F.  W.  Urich)  ;  Arroyo  di  los  Nogales,  Chihuahua, 
Mex.   (C.  H.  T.  Townsend) ;  San  Jose,  Costa  Rica,  Cordoba,  and 


SIMULIUM.  49 

Orizaba,  Mex.   (F.  Knab)  ;  Livingston  and  Alta  Vera  Paz,  Guate- 
mala (Sehwarz  and  Barber). 

A  translation  of  Bellardi's  description  of  the  male  of  Simulium 
metallicum  is  as  follows: 

Metallic  blue-black.  Base  of  antennae,  halteres,  fore  femora,  middle  portions 
of  fore  tibiae,  bases  of  mid  and  bind  tibiae,  and  bases  of  first  and  second  joints 
of  mid  and  bind  tarsi  vvbite.  Wings  byaline,  veins  ratber  indistinct.  Lengtb 
of  body,  2  mm. ;  wing  expanse,  5  mm. 

Xothing  is  said  as  to  whether  the  thorax  is  striped  or  not. 
Roubaud  found  a  female  in  the  Paris  Museum,  belonging  presum- 
ably to  the  original  lot  from  which  the  male  was  described,  and 
published  a  description  of  it  in  1906.1  He  did  not  redescribe  the 
male. 

Larva. — Similar  in  color  to  those  of  venustum  and  jenningsi  and 
about  the  same  size  as  the  latter.  The  labium  is  of  the  same  type 
as  those  of  this  group  also,  but  the  intermediate  teeth  between  the 
central  and  outer  teeth  are  very  small;  in  this  respect  it  is  more 
closely  allied  to  venustum,  though  there  appear  to  be  only  three 
distinct  lateral  ventral  setae,  as  in  jenningsi. 

Pupa. — The  species  has  eight  respiratory  filaments,  but  these 
differ  in  the  branching  from  piscicidiam,  as  shown  in  Plate  VI,  figure 
4.  The  cocoon  is  similar  to  that  of  venustum,  closely  woven  and 
found  on  leaves  and  stems  of  plants. 

The  foregoing  details  are  drawn  from  material  sent  in  by  Mr. 
F.  TV.  Urich,  from  Trinidad,  along  with  imagines  of  this  species. 

Simulium  meridionale  Ililey. 

Female. — Gray,  or  brown-black  with  very  thick  gray  dusting, 
opaque;  antenna?  and  palpi  brown-black,  the  former  but  little  paler 
at  base  in  some  specimens,  in  others  entirely  dark.  Scutum  with 
three  narrow  black  or  brown  stripes,  the  outer  two  curved,  sometimes 
almost  straight  on  anterior  portions;  pleurae  gray;  scutellum  some- 
times brownish  or  yellowish,  with  gray  dusting.  Abdomen  in  type 
gray  with  opaque  brown-black  cross-bands  on  segments  2-5  which 
occupy  the  whole  disk  on  center  but  taper  toward  sides,  segments 
6-8  and  portion  of  9  visible  gray-black  with  a  bluish  sheen.  This 
coloration  is  abnormal,  in  my  opinion,  and  is  very  probably  due  to 
the  fact  that  the  specimen  was  either  drawn  from  the  pupa  or  was 
prematurely  killed.  In  the  great  majority  of  specimens  before  me, 
including  a  large  number  of  the  reared  specimens  of  Riley's  original 
series,  the  abdomen  is  more  or  less  distinctly  banded  with  black  or 
brown  on  segments  2-4  only,  and  there  are  dorsal  spots  in  varying 

1  Bui.  Mus.  Hist.  Nat.  Paris,  vol.  13,  p.  519. 
16125°— 14 4 


50  AMERICAN   BLACK   FLIES   OR  BUFFALO   GNATS. 

degrees  of  intensity  on  the  other  segments.  Legs  black;  in  some 
specimens  brownish.  Wings  clear,  thick  veins  yellowish  or  brown- 
ish.   Halteres  yellow. 

Frons  narrow,  at  vertex  not  occupying  one-fourth  the  width  of 
head,  slightly  more  than  one-half  as  wide  at  lower  angle  as  at  upper 
angle  of  eyes,  surface  hairs  pale,  weak,  and  regularly  disposed ;  face 
distinctly  wider  than  frons  at  upper  angles,  one-fourth  longer  than 
wide,  hairs  as  on  frons;  proboscis  very  short,  in  none  of  the  speci- 
mens projecting  more  than  length  of  face;  palpi  black-haired. 
Scutum  with  very  short,  hairlike,  regular,  but  not  closely  placed, 
white  pilosity,  which  is  longer  on  posterior  fourth;  pleural  tuft 
yellowish  white;  scutellum  with  pale  hairs.  Abdominal  basal  scale 
gray,  the  fringe  pale  yellowish  white,  all  segments  with  distinct 
close-lying  pile  or  hairs,  which  are  white  in  color  and  much  longer 
at  apex  and  on  sides.  Legs  with  close-lying,  white,  hairlike  pilosity 
and  longer,  dorsal,  pale  hairs;  hind  tarsi  with  apex  of  basal  joint 
produced  on  posterior  surface,  second  joint  with  basal  scale  and 
constriction;  claws  bifid,  as  in  Plate  II,  figure  16  {Prosimulium 
pleurale).     Hairs  on  basal  portion  of  wing  veins  yellowish. 

Length,  2-3  mm. 

Kedescribed  from  type  specimens,  Friersons  Mill,  La.,  May,  1888, 
and  December,  1889,  and  a  number  of  other  specimens  from  Na- 
pinka,  Manitoba,  June  20,  1907  (F.  Knab),  and  Abbeville,  Xinety 
Six,  and  Greenwood,  S.  C,  April,  1912  (Jennings  and  King).  I 
have  also  before  me  a  series  of  specimens  (14)  taken  in  a  house  at 
Knoxville,  Tenn.,  by  E.  C.  Cotton,  which  may  be  the  form  described 
by  Townsend  as  S.  Occident  ale.1  Johannsen  considered  Townsend's 
species  as  a  small  variety  of  meridionale,  the  early  stages  of  the 
former  being  unknown.  The  Canadian  specimens  in  this  series  are 
much  larger  (3-4  mm.)  than  those  from  Tennessee  (1.5-2  mm.)  or 
South  Carolina  (2.5-3  mm.),  but  size  alone  is  not  a  reliable  criterion, 
and  structurally  the  insects  appear  to  me  to  be  identical.  It  is  pos- 
sible that  the  early  stages  may  prove  different  in  these  forms,  but 
none  of  the  characters  given  for  their  separation  by  Townsend  appears 
to  be  of  specific  value  in  the  imagines. 

There  are  some  specimens  in  the  collection  from  Conga ree,  S.  C, 
April  9,  1912  (Jennings  and  King),  which  have  the  thoracic  stripes 
practically  absent,  but  I  do  not  feel  justified  in  separating  them  as  a 
distinct  species,  as  in  other  respects  they  agree  with  meridionaler 

Male. — Velvety,  opaque  black.  Antennae  slightly  yellowish  on 
basal  two  joints  and  base  of  third.  Scutum  with  two  anterior  mar- 
ginal pollinose  spots  of  a  whitish  color,  lateral  and  posterior 
margins  similarly  pollinose;  when  worn  slightly  the  stripes,  so  dis- 
tinct  on   scutum   of  female,   may  be   indistinctly   traced:    prescutum 

iPgyche,    1801,    p.    107.  2  See    Addenda,    p.    63. 


SIMULIUM.  51 

brownish  or  yellowish;  pleurae  black,  paler,  brownish,  posteriorly, 
and  with  whitish  pollinosity ;  scutellum  brownish.  Abdomen  velvety 
black,  sides  of  first  segment,  under  basal  scale,  and  apical  two  to 
three  segments  whitish  pollinose.    Legs  brown,  tarsi  darker. 

Head  of  the  usual  male  form  in  this  genus;  face  hairs  pale; 
postocular  cilia  pale,  with  numerous  longer,  intermixed  black  hairs. 
Scutum  with  rather  long,  white,  hairlike  pilosity,  which  is  most 
closely  placed  on  margins;  pleural  tuft  pale;  scutellar  hairs  white. 
Abdominal  fringe  brownish  yellow;  all  segments  with  pale,  rather 
short,  dorsal  hairs,  and  long  lateral  hairs  of  same  color.  Legs  with 
pale  hairlike  pubescence  which  is  longer  than  that  of  the  legs  of 
female;  claws  trifid.  The  wing  venation  is  as  in  female,  but  the 
wings  are  vitreous.    Halteres  brown. 

Redescribed  from  the  original  specimens  bred  from  same  pupal 
material  as  the  female  type. 

The  larva  and  pupa  of  this  species  bear  a  strong  resemblance  to 
those  of  venustum  Say.  The  larva  may  be  distinguished  from  that 
of  venustum  by  the  absence  of  the  short  bristles  from  the  apical 
joint  of  the  maxillary  palpus,  the  larger  size  of  the  central  tooth  of 
the  labium  as  compared  with  the  outer  lateral  one,  and  also  the 
presence  of  only  three  to  four  ventral  lateral  bristles.  The  pupal 
respiratory  filaments  number  six,  but  the  pairs  divide  at  very  near 
the  base  instead  of,  as  in  venustum,  appreciably  beyond  the  base. 

This  species  has  the  reputation  of  being  a  biter,  but  the  only 
record  in  the  collection  is  that  borne  by  one  specimen  from  Myrtle. 
Ga.,  April  3,  1906  (A.  A.  Girault)— "on  Homo,"  "found  sucking 
blood  from  hand." 

Simulium  tamaulipense  Townsend. 
The  following  is  a  copy  of  the  original  description  by  Townsend : 

9 .  Length,  1£  mm.  Near  8.  meridionale,  but  smaller  and  the  outer  one  on 
each  side  of  the  three  thoracic  lines  not  curved  outward  at  posterior  end.  Eyes 
velvet  black,  face  and  front  silvery;  the  front  with  usually  a  trace  of  linear 
black  vitta  in  one  specimen  very  distinct,  in  another  entirely  wanting.  Antennse 
yellowish,  with  a  silvery  covering.  Thorax  silvery,  with  three  longitudinal 
lines;  the  middle  one  longest,  very  narrow  and  linear;  the  outer  ones  heavier, 
straight,  slightly  divergent  posteriorly.  Looked  at  directly  from  above,  the  outer 
lines  appear  curved,  outwardly  convex.  Scutellum  and  metascutum  below 
scutellum,  both  brownish  in  some  lights  but  in  others  they  seem  to  be  wholly 
silvery,  the  various  portions  appearing  different  in  color  to  the  view  at  the 
same  time.  Abdomen  silvery,  but  the  third  and  fourth  segments  wholly 
brownish,  sometimes  with  a  round  median  silvery  spot  on  each.  Legs  yel- 
lowish, shaded  with  silvery,  tarsi  blackish  or  brownish;  hind  metatarsi  yellow- 
ish, except  at  distal  end.  Wings  clear,  whitish,  veins  dilute  pale  yellowish. 
Halteres  and  wing  bases  pale  dilute  yellowish. 

Four  $'s,  Reynosa,  Tamaulipas  [Mexico].  A  small  species  taken  on  car 
windows  of  railway  train,  May  10th. 

Described  from  four  dried  specimens. 


52  AMERICAN   BLACK   FLIES   OR  BUFFALO   GNATS. 

This  description  fits  memdiondle  in  practically  every  respect, 
except  that  the  form  of  the  tarsal  claws  is  not  indicated.  Though 
the  outer  stripes  are  given  as  "  not  curved  outward  at  posterior  end," 
they  appear  to  represent  a  form  often  met  with  in  this  species,  where 
the  apices  of  the  side  stripes  are  indistinct.  I  consider  it  highly 
probable  that  this  is  merely  a  synonym  of  meridionale  Riley,  but  I 
have  not  seen  the  types,  and  there  are  no  disadvantages  to  be  appre- 
hended from  retaining  tamaulipense  as  a  possible  distinct  species 
until  some  one  examines  the  original  specimens. 

Simulium  griseum  Coquillett. 

Female. — Opaque  gray-brown;  frons  and  face  thickly  white-gray 
dusted;  antenna?  brown,  the  basal  two  joints  and  base  of  third  yel- 
low; palpi  brown-black.  Scutum  gray-brown,  very  thickly  covered 
with  white  dusting  except  on  center,  where  there  is  a  more  or  less 
distinct  longitudinal  stripe,  and  on  lateral  and  posterior  margins, 
where  the  ground  color  becomes  yellowish;  pleura?  gray,  paler 
posteriorly ;  scutellum  yellow ;  postscutum  gray-black.  Abdomen 
tawny  yellow,  first  five  segments  with  a  rounded,  opaque  black, 
dorso-central  spot,  that  on  the  segment  beneath  basal  scale  the  least 
distinct,  remaining  segments  yellow  with  slightly  darkened  dorsum; 
sometimes  in  addition  to  the  central  spot  there  are  indications  of  lat- 
eral spots  on  the  first  four  segments.  Legs  yellow,  black  as  follows : 
Mid  and  hind  coxa?;  entire  fore  tarsi;  hind  femora;  hind  tibia?; 
basal  three  joints  of  both  mid  and  hind  tarsi  at  apices;  and  last  two 
joints  of  mid  and  hind  tarsi  entirely.  Wings  clear,  thick  veins  yel- 
lowish.    Halteres  yellow. 

Frons  divergent-sided,  its  width  at  upper  angle  of  e3^es  equal  to 
its  length  from  lower  to  upper  angle  and  one-fourth  wider  than  at 
lower  angle,  surface  hairs  yellow;  face  as  long  as  frons,  subquadrate, 
surface  hairs  yellow;  postocular  cilia  pale.  Scutum  with  pale  yel- 
low pilosity  which  is  regularly  distributed  and  elongate  scale-like, 
short  except  on  posterior  margin;  viewed  from  behind  there  is  an 
indication  of  two  white  spots  on  the  anterior  margin  of  scutum  at 
the  inner  angle  of  prescutum;  pleural  tuft  yellow  ;  hairs  on  scutellum 
yellow.  Abdominal  basal  scale  yellow  and  yellow-haired:  surface 
hairs  on  abdomen  yellow.  Legs  with  pale  yellow  pilosity  and  a  few 
scattered  upright  brown  hairs  which  are  most  noticeable  at  apices 
and  on  dorsal  surfaces  of  tarsal  joints:  basal  joint  of  hind  tarsi  with 
apical  extension,  second  with  basal  scale  and  constriction,  claws  as 
shown  in  Plate  IT,  figure  7  (vcnuxtttm).  Wing  venation  normal, 
hairs  on  wing  base  nol  numerous,  yellow. 

Length,  1.5-2  mm. 


SIMULIUM.  53 

Two  females  marked  Colorado,  No.  1G05  (C.  F.  Baker)  ;  one  female 
Pecos,  N.  Mex.,  June  28,  on  horse  (M.  Grabham)  ;  and  three  females 
Inyo  County  (?),  Cal.  (A.  Davidson). 

The  first  mentioned  specimens  are  the  type  lot  and  are  slightly 
smaller  than  those  from  California. 

Male. — Eyes  of  the  normal  form  of  the  males  in  this  genus;  face 
white-pollinose,  antenna)  brown,  paler  on  basal  two  joints;  postocular 
cilia  pale.  Scutum  with  white  pollinosity,  which  is  distinctly  pearl- 
aceous  on  anterior  margin;  the  whole  disk  pollinose  except  a  poste- 
riorly abbreviated,  central,  longitudinal,  opaque  black  stripe,  and 
faint  indications  of  two  much  shorter  lateral  stripes;  pilosity  hair- 
like, white;  prescutum  yellow;  pleura?  brown,  darker  on  center; 
scutellum  yellow.  Abdomen  opaque  black;  segment  below  basal 
scale  yellow,  fifth  segment  and  postero-lateral  margins  of  the  apical 
segments  yellow.  Legs  colored  as  in  female,  but  the  hind  femora  are 
only  darkened  at  apices,  and  the  claws  are  trifid.  In  other  respects 
similar  to  female.  One  specimen,  Colorado,  No.  1605;  no  other 
data.     It  bears  the  type  label  "  Cat.  No.  10381  U.  S.  N.  M." 

The  early  stages  are  unknown. 

Simulium  vittatum  Zetterstedt 

Female. — Gray,  opaque,  or  opaque  black  with  very  thick  gray 
dusting,  except  on  the  portion  of  body  given  as  black  in  description. 
Antennas  brown,  basal  two  joints  yellowish;  palpi  and  proboscis 
brown.  Scutum  with  a  straight  dorso-central  stripe  which  is  some- 
times linear,  but  generally  with  a  brownish  suffusion,  broadest  at 
anterior  third;  this  stripe  reaches  the  anterior  margin  and  stops  at 
about  posterior  fourth;  on  either  side  of  this  central  stripe  there  is 
a  bicurved  stripe  which  is  triangularly  dilated  at  anterior  extremity, 
then  much  narrowed,  bent  inward  on  anterior  half,  and  bent  out- 
ward and  slightly  dilated  on  its  posterior  half,  joining  the  central 
stripe,  or  almost  so,  with  an  inward  curve  at  posterior  fourth ;  later- 
ally beyond  these  two  stripes  are  other  two  which  stop  much  short 
of  the  prescutum,  and  also  of  the  end  of  central  stripe;  generally 
these  outer  stripes  are  dilated  anteriorly;  pleura?  unicolorous  gray; 
scutellum  slightly  darkened  on  disk.  Abdomen  with  basal  scale  with 
a  black  central  spot ;  first,  second,  and  third  segments  with  a  basal 
crossband  of  black  which  is  produced  centrally;  the  next  three  seg- 
ments with  a  posteriorly  tridentated,  black  crossband;  the  fourth 
and  fifth  with  an  additional  lateral  black  spot;  apical  segments 
darkened.  Legs  black,  all  tibia?  whitish  yellow  on  basal  half,  the 
division  between  the  colors  generally  very  abrupt,  mid  tarsi  with 
basal  joint  yellow  or  whitish  at  base,  hind  tarsi  with  two  basal  joints 


54  AMERICAN   BLACK   FLIES   OR  BUFFALO   GNATS. 

pale  at  base,  tibise  whitish  dusted,  dorsally,  at  base.  Wings  clear, 
thick  veins  brown.    Halteres  yellow. 

Frons  slightly  divergent-sided,  less  than  one-third  as  wide  as  head 
at  upper  angle  of  eyes,  surface  hairs  pale,  sparse ;  face  subquadrate, 
as  broad  as  frons  at  upper  angle,  surface  hairs  pale,  more  numerous 
than  on  face,  postocular  cilia  pale,  with  a  few  intermixed,  longer, 
blackish  hairs.  Scutum  with  whitish  hairlike  pilosity,  a  few  longer, 
dark  hairs  in  posterior  depression ;  pleural  tuft  pale ;  scutellum  with 
upright  pale  hairs.  Abdominal  basal  fringe  white;  apical  segments 
of  abdomen  with  sparse,  short,  white  hairs.  Legs  with  white  pilosity 
and  longer,  brownish,  upright,  dorsal  hairs,  fore  tarsi  slightly  di- 
lated, the  apical  paired  hairs  absent  or  very  inconspicuous;  claws 
simple  (PI.  II,  fig.  9).     Wing  venation  normal. 

Length,  2-3  mm. 

Hale. — Opaque,  velvety  black.  Antennae  black,  sometimes  slightly 
paler  at  base.  Scutum  with  anterior,  posterior,  and  lateral  margins 
white  pollinose;  in  some  lights  there  are  visible  two  straight  longi- 
tudinal dorsal  stripes  which  do  not  reach  beyond  middle  of  disk; 
in  one  or  two  cases  there  is  an  indication  of  the  Avhite  spots,  which 
show  in  many  specimens  of  pictipes  Hagen,  on  the  anterior  margin 
slightly  nearer  center  than  stripes ;  pilosity  yellow,  hairlike ;  pleural 
tuft  brownish.  Basal  fringe  of  abdomen  brown,  abdominal  segments 
opaque  black,  sides  of  segments  1-3  generally  silvery  pollinose.  Legs 
colored  as  in  female,  but  the  mid  tibia?  generally  less  distinctly  pale 
at  base,  and  the  hairs  longer;  claws  trifid.  Otherwise  as  female. 
Hind  leg  of  male  figured  on  Plate  V,  figure  2. 

There  are  specimens  in  the  collection  which  I  consider  as  belonging 
to  this  species  from  the  following  localities:  Glencoe,  Xebr.  (E.  A. 
Dodge)  ;  Richmond,  Ind.  (W.  S.  Ratcliff)  ;  Minnesota  (Lugger)  ; 
Grand  Rapids,  Minn.,  August  18,  189G;  Niagara  Falls,  November, 
1896,  Pikes  Peak,  Colo.,  10.000  feet,  September  17  (T.  D.  A.  Cock- 
erell)  ;  Death  Valley.  Cal.,  April,  1891  (Koebele)  :  Los  Angeles.  Cab. 
July  (collection  Coquillett)  ;  Onaga,  Kans.,  in  hog's  ear;  Yakutat 
and  Kadiak,  Alaska,  June-July  (T.  Kincaid)  ;  Spartanburg,  S.  C. 
July.  1912  (Jennings  and  King)  ;  Sabina,  Tex.,  March  22,  1911  (C.  T. 
Atkinson)  :  Victoria,  Tampico,  Mexico,  December,  1910,  biting  burros 
(F.  C.  Bishopp).  There  are  examples  of  this  species  in  the  Illinois 
State  Laboratory  of  Natural  History  collection  from  Ottawa  and 
Algonquin,  111.  The  species  has  been  found  commonly  in  all  stages 
at  Havana  on  the  Illinois  River.  The  larva'  and  pupa'  have  been 
< ;ikcn  in  the  Illinois  River  and  also  in  various  creeks  in  Illinois. 

Tbere  are  only  two  cases  in  which  this  species  is  given  as  attack- 
ing animals  in  the  foregoing  list.  Johannsen  does  not  give  any  indi- 
cation  of  its  habits,  but  Lugger,1   in   referring  to  this  species  as 

1  Bui.    is,  Minn.  Agt.  Dzp.  Stn..   1896,  ]>.  207. 


SIMULIUM.  55 

&.  tribulatum,  deals  at  some  length  with  its  habits.  Its  distribution  is 
quite  the  widest  of  any  of  the  American  species.  It  may  be  that 
there  are>more  than  one  species  in  the  material  before  me,  but  I  can 
not  find  any  characters  to  separate  the  Alaskan  specimens  from  those 
of  Mexico.  Argus  Williston  is,  I  consider,  identical  with  vitta&um. 
Sometimes  the  thorax  gets  wet  and  the  stripes,  being  visible  only 
through  the  presence  of  the  pollinosity  in  good  specimens,  become 
indistinct  or  practically  invisible.  There  is  nothing  strange  in  the 
fact  that  they  are  not  mentioned  in  Williston's  original  description  of 
his  species,  if  his  specimen  was  not  in  good  condition. 
The  larva,  as  described  by  Johannsen,  is  as  follows : 

Somewhat  mottled  gray,  the  sides  of  each  segment  blackish.  The  head  is 
of  the  usual  reddish  brown  color;  the  pale  yellow  antennae  long  and  cylindrical, 
the  second  joint  about  one-third  the  length  of  the  first,  the  third  is  a  pointed 
process  at  tip  of  the  second.  The  fans  have  about  40  rays,  the  cilia  being 
relatively  minute.  The  mandibles  are  provided  with  three  large  apical  teeth 
besides  the  row  of  secondary  ones;  the  apical  pair  of  bristles  is  present.  The 
maxillary  palpus  has  a  few  spines,  and  a  tuft  of  a  few  spines  on  the  basal 
joint.  *  *  *  The  labium  has  an  elongated  middle  tooth,  those  at  the  end 
nearly  as  long,  the  intermediate  ones  short,  and  there  are  six  bristles  in  each 
of  the  two  longitudinal  rows  on  the  ventral  surface.  The  three  blood  gills  at 
caudal  end  are  unbranched. 

The  pupal  respiratory  organs  are  as  shown  in  Plate  IV,  figure  4. 

The  cocoon  is  similar  to  that  of  venustum  Say,  and  is  attached  to 
leaves  or  plant  stems  in  the  water.  Occasionally  there  are  only  15, 
instead  of  16,  filaments  in  the  respiratory  organs.  I  have  seen  the 
pupa?  from  Spartanburg,  S.  C.  (Jennings  and  King). 

Simulium  pictipes  Ha  gen. 

Female. — Dark  gray,  opaque;  frons  and  face  very  thickly  white- 
dusted;  antennae  brown,  yellowish  on  basal  two  joints;  palpi  brown- 
black.  Scutum  thickly  gray-dusted,  with  three  brown  or  black 
stripes,  the  central  one  straight,  the  lateral  ones  curved,  and  dilated 
slightly  anteriorly,  the  dilated  portion  with  white  pollinose  spot 
when  viewed  from  behind ;  pleurae  gray,  opaque ;  scutellum  and  post- 
scutum  concolorous.  Abdomen  gray,  segments  2-A  broadly  opaque 
brown  or  black-brown  on  dorsum,  the  one  below  basal  scale  only 
slightly  darker  on  center.  Legs  dark  gray,  only  the  bases  of  tibiae 
and  bases  of  first  tarsal  joints  of  mid  and  hind  legs  paler,  except  in 
immature  specimens,  when  the  legs  may  be  yellowish,  but  they  never 
^how  so  distinctly  bicolored  as  in  virgatum  or  hunteri.  Wings  gray- 
ish, the  veins  rather  more  distinct  than  usual.  Halteres  yellow, 
darker  at  base  of  stalk. 

Frons  slightly  raised  in  center,  divergent-sided,  as  long  as  broad 
at  upper  angle  of  eyes,  where  it  is  one-fourth  wider  than  at  lower 
angle  of  eyes:  surface  hairs  white,  with  a  slight  admixture  of  black 


56  AMERICAN   BLACK   FLIES   OR  BUFFALO   GNATS. 

ones,  most  numerous  on  lateral  margins;  face  as  broad  as  frons  at 
center,  slightly  longer  than  broad,  the  surface  hairs  yellowish  white : 
palpi  black  haired;  postocular  cilia  white  and  black  iiftermixed, 
the  black  hairs  strongest.  Scutum  with  yellowish  white,  regular, 
hairlike  pilosity,  anterior  angles  with  short  intermixed  black  hairs, 
posterior  fourth  with  distinct,  long,  black,  upright  hairs;  pleural 
tuft  whitish;  post-spiracular  area  haired;  scutellum  with  whitish 
pilosity  and  upright  black  hairs.  Abdominal  basal  scale  opaque 
black,  fringe  pale,  whitish;  surface  hairs  on  abdomen  short,  pale 
yellow  or  whitish.  Legs  with  whitish  pilosity  and  some  upright 
black  hairs,  which  are  most  noticeable  on  dorsal  surfaces  and  tarsal 
joints,  the  paired  apical  fore  tarsal  hairs  not  so  conspicuous  as  in 
venustum  and  its  allies;  tarsal  claws  simple  (PI.  II,  fig.  10). 

Length,  3-4  mm. 

One  female  from  Ithaca,  N.  Y.,  September  2,  1888  (Dr.  L.  O. 
Howard),  and  three  reared  females  from  Rosslyn,  Va.,  October  5, 
1912  (J.  E.  Malloch),  are  in  the  collection.  I  have  also  seen  larval, 
pupal,  and  adult  material  from  South  Carolina  (Jennings  and  King) . 

Male. — Opaque  velvety  black.  Basal  two  joints  of  antennae 
slightly  yellowish.  Scutum  with  anterior  angles  and  lateral  and 
posterior  margins  broadly  white-pollinose ;  sometimes  there  are  two 
small  spots  on  the  anterior  margin,  nearer  the  center  than  the  large 
patches  on  anterior  angles  of  scutum  behind  prescutum,  and  in 
some  specimens  there  are  also  two  central  faint  whitish  longitudinal 
stripes;  pleura?  whitish  dusted,  postscutum  with  silky,  white  jDolli- 
nosity.  Abdomen  with  first  segment  under  basal  scale  and  sides  of 
fourth  to  seventh  silvered.  Legs  black,  the  knees  and  base  of  hind 
metatarsus  more  or  less  distinctly  yellowish.  Wings  .clear;  thick 
veins  brown.     Halteres  yellow. 

Hairs  on  face  and  palpi  brown,  postocular  cilia  brown ;  pilosity  on 
thorax  yellow  and  hairlike,  short  on  disk  of  scutum,  longer  anteriorly, 
laterally,  and  posteriorly,  and  with  a  few  black,  upright  hairs  inter- 
mixed on  posterior  fourth;  pleural  tuft  pale  brown;  scutellum  with 
yellow  pilosity  and  long,  upright,  brown  hairs.  Basal  abdominal 
fringe  brownish  yellow,  surface  hairs  on  abdomen  brown.  Legs 
with  yellow  pilosity,  which  is  most  noticeable  on  femora  and  tibia\ 
and  long,  upright,  dorsal,  black  hairs,  the  paired  fore  tarsal  hairs 
present  on  joints  1-3;  fore  tarsus  not  thickened,  hind  tarsus  with 
basal  joint  narrower  than  thickest  portion  of  hind  tibia1 ;  claws  trinYt. 
Size  and  venation  as  in  female. 

There  are  a  number  of  specimens  before  me  from  Ithaca,  X.  Y. 
(Dr.  L.  O.  Howard),  most  of  which  have  the  anterior  punctiform 
marlcs  and  dorso-central  stripes  distinct.  The  localities  for  theother 
specimens  in  the  collection  are   Rosslyn,  Ya.    (F.   Knab),  one  reared 


SIMULIUM.  57 

specimen  from  same  locality  (J.  K.  Malloch),  and  a  reared  scries 
from  South  Carolina  (Jennings  and  King). 

Larva. — Length  9  to  12  mm.  Sometimes  almost  entirely  black  in 
color.  The  fans  (PL  III,  fig.  5)  have  about  60  rays  which  have 
regularly  spaced  seta3  and  slightly  shorter  and  much  finer  ciliae  be- 
tween them.  The  mandibles  are  as  figured  on  Plate  III,  figure  2,  and 
respiratory  organs  as  in  Plate  VI,  figure  G.  The  labium  has  the  cen- 
tral tooth  longest  and  in  general  outline  approaches  the  venustum 
type  of  dentation  (PI.  Ill,  fig.  4).  So  far  as  my  experience  goes — 
and  that  of  Messrs.  Jennings  and  King  substantiates  it — the  larvae 
of  this  species  are  always  found  on  rock  surfaces  where  there  is  a 
rapid  current,  such  as  on  waterfalls,  and  are  difficult  of  detection 
owing  to  their  dark  color  which  harmonizes  well  with  that  of  the 
rocks.  If  such  conditions  are  essential  to  the  larvae  it  will  account 
for  the  presence  of  the  species  in  certain  suitable  localities  and  its 
absence  from  others  where  such  conditions  do  not  prevail. 

Pupa. — The  respiratory  filaments  consist  of  nine  branches  (PL  IV, 
fig.  2).  The  cocoons  are  slipper  shaped  and  yellow-brown  in  color 
(PL  VI,  fig.  8).  They  are  placed  close  together  on  the  rock  surface 
with  the  open  ends  pointing  downstream.  Owing  to  their  pale  color 
and  their  being  placed  closely  together  they  are  easily  seen  on  the 
dark  surface  of  the  rocks.  It  is  not  difficult  to  obtain  imagines  from 
the  pupae  if  they  are  kept  on  damp — not  wTet — cotton. 

The  adult  female  will  bite  horses,  but  there  is  no  published  record 
of  its  attacking  human  beings  that  I  can  find.  One  specimen  in  the 
collection  of  the  U.  S.  National  Museum  from  Plummers  Island,  Md., 
November  3,  1901,  bears  a  label  with  the  word  "biting,"  but  Mr. 
H.  S.  Barber,  who  took  the  specimen,  does  not  recollect  the  particu- 
lars of  its  capture. 

Simulium  virgatum  Coquillett. 

Female. — Black-brown,  opaque.  Frons  and  face  with  thick 
whitish  gray  dusting;  antennae  brown,  the  two  basal  joints  yellow; 
palpi  black-brown.  Scutum  distinctly  striped,  central  stripe  nar- 
row, linear,  lateral  pair  curved,  the  anterior  dilated  portion  filled 
with  white  pollinosity  forming  a  pear-shaped  spot,  the  anterior  angle 
of  which  is  as  broad  as  the  space  between  the  spots;  lateral  margins 
darkened;  pleurae  distinctly  white-dusted,  scutellum  concolorous with 
scutum;  postscutum  with  white  silky  pollinosity.  Abdomen  black- 
brown,  opaque  on  basal  four  segments,  subshining  on  apical  four,  all 
segments  with  distinct,  narrow,  white-pollinose  fasciae  on  hind  mar- 
gins. Legs  yellow,  brown,  or  black-brown,  as  follows:  Apices  of 
femora,  a  narrow  ring  or  spot  at  bases  and  apical  halves  of  all  tibiae ; 
entire  fore  tarsi;  apices  of  first  and  second  and  remaining  joints  of 


58  AMERICAN  BLACK   FLIES   OR  BUFFALO   GNATS. 

mid  and  hind  tarsi  (PL  V,  fig.  3).  Wings  slightly  grayish,  thick 
veins  brown.     Halteres  yellow. 

Frons  divergent-sided,  above  antennae  more  than  half  as  broad  as 
at  upper  angle  of  eyes,  surface  hairs  brown,  upright,  and  regularly 
distributed ;  face  not  as  long  as  frons  and  slightly  longer  than  broad, 
surface  hairs  pale  and  shorter  than  those  on  frons;  hairs  on  palpi 
pale;  postocular  cilia  pale,  with  an  admixture  of  brown  hairs. 
Scutum  with  white  pilosity,  which  is  short,  close-lying,  and  regular 
except  on  margins,  where  it  is  rather  longer  and  looser;  a  few  short 
brown  upright  hairs  are  present  on  lateral  anterior  angles  and  many 
longer  ones  on  posterior  fourth ;  pleural  tuft  grayish  white ;  scutellum 
with  close-lying  white  pilosity  and  long,  upright,  brown  marginal 
hairs.  Abdominal  basal  scale  brown,  fringe  white;  segments  of 
abdomen  almost  bare,  only  a  few  scattered  brown  hairs  present,  those 
on  apical  segments  most  distinct.  Legs  with  close-lying,  short,  pale 
pilosity  and  longer,  brown,  upright  hairs  on  dorsal  surfaces ;  the  nor- 
mal paired  apical  hairs  present  on  the  fore  tarsi  and  longer  hairs  also 
on  hind  tarsal  joints  2-3;  hind  tarsi  with  basal  joint  produced  and 
second  joint  with  basal  scale  and  constriction  (PI.  V,  fig.  5)  ;  claws 
with  sub-basal  tooth  (PI.  II,  fig.  11).  Venation  of  wings  normal 
except  that  the  cross- vein  is  at  slightly  beyond  middle  of  subcosta ; 
hairs  on  basal  part  of  wing  brown,  anal  marginal  hairs  white. 

Length,  3-1  mm. 

Redescribed  from  the  two  type  specimens  from  Las  Vegas,  X.  Mex., 
August  (H.  S.  Barber).  These  have  the  scutum  indistinctly  reddish 
and  differ  in  this  respect  only  from  a  series  in  the  collection  from 
Los  Angeles,  Cal.,  which  was  taken  in  June  and  July.  I  can  find  no 
other  characters  which  would  justify  me  in  separating  them  as  dis- 
tinct species. 

Male. — Opaque  black-brown.  Face  white-dusted;  antenna?  brown, 
basal  two  joints  yellowish;  palpi  black-brown.  Scutum  with  two 
distinct  silvery-white  stripes  on  dorsum;  these  stripes  are  anteriorly 
slightly  convergent  and  terminate  with  an  outward  curve  on  anterior 
margin  of  scutum ;  they  do  not  extend  posteriorly  beyond  the  last 
fourth  of  disk;  lateral  margins  and  anterior  angles  of  scutum  white- 
pollinose;  pleura4  white-pollinose;  postscutum  with  silky,  white  polli- 
nosity.  Abdomen  opaque  black  at  base,  apical  three  segments  slightly 
shining,  first  segment  below  basal  scale  and  fifth  almost  entirely 
silvery  white,  renter  yellowish  laterally.  Legs  yellow,  blackened  as 
follows:  Mid  and  hind  coxa?;  apices  of  all  femora  and  tibia4  ;is  well 
as  slightly  at  base  of  latter;  entire  fore  tarsi;  apices  of  basal  joint  of 
mid  and  hind  tarsi:  apical  four  joints  of  mid  and  all  but  base  of 
M-ru nd  joint  of  hind  tarsi.  Wings  grayish,  thick  veins  brown. 
Halteres  with  clear  yellow  knobs  and  darkened  stalk. 


SIMULIUM.  59 

Hairs  on  face  pale  brown,  on  palpi  brown,  postocular  cilia  dark 
brown.  Pilosity  on  scutum  regular,  rather  scalelike,  golden  yellow. 
a  few  dark  hairs  on  anterior  angles  and  longer  and  more  numerous 
hairs  of  black-brown  color  on  posterior  fourth;  pleural  tuft  yellow; 
scutellum  with  yellow  pilosity  and  long  upright  brown  hairs;  basal 
fringe  and  surface  hairs  on  abdomen  pale  yellow.  Pilosity  on  legs 
almost  white,  except  on  darkened  portions  where  it  is  pale  brown, 
numerous  long  pale  brown  dorsal  hairs  on  all  joints,  the  fore  tarsi 
with  paired  apical  hairs  on  joints  1  and  3,  those  on  joint  2  not  so 
distinct;  fore  tarsi  not  thicker  than  mid  pair,  thinner  than  fore  tibiae; 
hind  legs  as  in  Plate  V,  figure  4;  claws  trifid.  Wings  and  size  as  in 
female. 

Redescribed  from  the  type  specimen,  Las  Vegas,  N.  Mex.  (H.  S. 
Barber).  There  is  another  specimen  from  the  same  locality  in  the 
collection,  also  taken  by  Mr.  Barber. 

Nothing  is  known  of  the  early  stages  of  this  species. 

Simulium  hunteri,  new  species. 

Female, — Black;  frons  shining  black,  face  white-dusted.  Scutum 
three-striped,  opaque;  pleura?  opaque  black,  gray-dusted.  Abdo- 
men opaque,  velvety  black  on  basal  four  segments,  shining  black  on 
apical  four.  Legs  black,  yellow  as  follows:  Coxae,  trochanters,  and 
dorsal  surface  of  tibiae  of  fore  legs ;  trochanters,  bases  of  femora  and 
tibiae,  and  basal  two-thirds  of  first  tarsal  joint  of  mid  and  hind  legs; 
basal  third  of  second  hind  tarsal  joint.  Wings  grayish,  thick  veins 
brown ;  halteres  yellow,  darkened  at  base  of  stalk. 

Frons  with  sides  divergent,  about  two-thirds  as  wide  above  an- 
tennae as  at  vertex,  undusted,  surface  with  yellow  scale-like  pilosity 
and  upright  black  hairs  on  lateral  and  posterior  margins ;  face  thickly 
white-dusted,  about  one-fourth  longer  than  broad,  as  broad  as  frons 
at  upper  angle  of  eyes,  surface  hairs  yellow,  with  some  darker,  brown 
ones  mixed;  palpi  black,  pale-haired;  antennae  black,  yellowish  on 
basal  two  and  base  of  third  joints.  Scutum  gray-dusted,  with  irregu- 
larly arranged,  golden  yellow,  scale-like  pilosity,  and  with  two 
large  white  pollinose  spots  on  anterior  margin  which  are  each  more 
than  twice  as  broad  anteriorly  as  the  black  space  between  them; 
these  spots  are  only  visible  when  viewed  from  behind  and  occupy  the 
dilated  anterior  portions  of  the  posteriorly  narrower  black  stripe; 
viewed  from  in  front  and  above  the  dorsum  of  scutum  has  a  central, 
black,  narrow  stripe  and  two  curved  stripes  beyond  them,  as  well  as 
an  indication  of  a  narrow  lateral  stripe  on  each  side ;  pleural  tuft  and 
hairs  on  postspiracular  area  brownish  yellow;  scutellum  with  close- 
lying  yellow  pilosity  and  upright  black  hairs.  Abdominal  basal  scale 
brown  or  black,  fringe  yellow ;  lateral  posterior  margins  of  abdominal 


60  AMEKICAN  BLACK   FLIES   OR  BUFFALO   GNATS. 

segments  gray-dusted,  apical  segments  with  numerous  black  hairs  and 
a  few  intermixed  pale  scales,  the  hairs  at  apex  long.  Legs  with  long, 
yellow,  scale-like  pilosity  on  femora  and  upright,  dorsal,  black  hairs 
on  these  as  well  as  tarsi,  the  normal  paired  fore  tarsal  hairs  present 
on  apices  of  first  and  third  joints;  hairs  on  tarsi  concolorous  with 
joints;  claws  with  subbasal  tooth  (see  PI.  II,  fig.  3).  Wings  with 
venation  normal.    Halteres  pale  yellow,  darkened  at  base  of  stalk. 

Length,  3.5-4  mm. 

Type.—Qzt.  No.  15413,  U.  S.  National  Museum. 

Type  locality,  Virginia  Dale,  Colo.,  September  31,  1912  (collector 
Bishopp).  Submitted  for  identification  by  Mr.  TV.  D.  Hunter  (No. 
30G5).  One  specimen  from  Glenora,  British  Columbia,  and  another 
from  Ainsworth,  British  Columbia,  evidently  belong  to  this  or  a 
closely  allied  species,  but  their  condition  is  too  poor  to  say  for  certain. 

This  species  is  very  close  to  virgatum  Coquillett,  but  the  legs  are 
much  darker  in  color ;  this  character  is  very  consistent  throughout  the 
series  of  13  specimens),  and  the  frons  is  also  in  most  of  the  specimens 
entirely  glossy  black.  There  is  a  slight  dusting  present  on  one  or  two 
of  the  specimens  in  the  series,  but  nothing  like  the  thick  white  pol- 
linosity  which  is  found  on  that  of  virgatum. 

None  of  the  specimens  of  virgatum  bear  any  label  as  to  habits,  but 
the  type  series  of  hunteri  was  taken  on  cows.  The  early  stages  are 
unknown  in  this  species. 

Simulium  glaucum  Coquillett. 

Male. — Black,  opaque.  Antennae  and  palpi  black;  face  white- 
dusted.  Scutum  with  distinct  white  pollinosity,  which  is  bright 
silvery  on  two  triangular  patches  on  the  anterior  margin  dorsad  of 
the  lateral  extensions  of  the  prescutum;  central  opaque  black  stripe 
broad  and  well  defined  anteriorly,  linear  and  diffused  posteriorly; 
on  either  side  of  this  stripe  is  an  abbreviated  linear  mark  which  is 
evidently  the  rudiment  of  the  dorso-lateral  line  of  virgatum,  and 
nearer  the  lateral  margin  is  a  broader  black  stripe  which  is  dif- 
fused on  margins  and  anteriorly  abbreviated;  pleurae  white-pol- 
linose;  scutellum  slightly  pollinose.  Abdomen  opaque  black,  sides  of 
segment  below  basal  scale  and  apical  four  segments  laterally  silvered. 
Legs  black;  femora  paler  at  apices;  tibiae  and  basal  joints  of  mid 
and  hind  tarsi  broadly  yellow  at  bases;  second  joint  of  hind  tarsi 
pale  at  base.  Wings  clear,  thick  veins  yellowish.  Halteres  yellow, 
base  of  stalk  blackened. 

Face  hairs  and  postocular  cilia  pale.  Scutum  with  white,  hair- 
like  pilosity,  which  is  longer  posteriorly  and  on  the  margins; 
pleura]  lufl  whitish  yellow;  hairs  on  scutellum  pale,  upright.  Basal 
abdominal  fringe  yellow,  in  .some  lights  brown;  lateral  hairs  on 
abdominal   segments    white.     Legs    with    pale    pilosity    and    longer, 


SIMULIUM.  61 

upright,  dorsal  pale  hairs,  which  are  conspicuous  on  posterior  surface 
of  fore  femora;  fore  tarsi  not  dilated,  the  paired  apical  hairs  absent  : 
hind  tarsus  of  the  normal  Simulium  form;  claws  trifid.  Surface 
hairs  and  short  bristles  on  wing  veins  brownish  yellow. 

Redescribed  from  type  specimen.  Locality,  Kansas  City,  Mo. 
(C.  F.  Adams). 

This  species  belongs  to  the  same  group  as  virgatum  Coquillett  and 
hunteri)  new  species.  The  male  of  the  latter  is  unknown,  and  it  is 
possible  that  this  may  be  identical  with  it,  but  it  is  not  unlikely  that 
it  may  belong  to  a  quite  distinct  species.  There  is  very  little  re- 
semblance between  the  males  and  females  of  any  species  in  this  genus 
and  it  is  difficult  to  associate  them  correctly. 

The  early  stages  and  the  female  are  unknown. 

GROUP  E. 

Species  with  two  or  four  stripes  on  scutum ;  the  stripes  straight  or 
very  slightly  curved,  white  or  pearlaceous  pollinose. 

TABLE  OF   SPECIES. 

1.     Stripes  on  scutum  not  curved ;  scutelluin  with  close-lying  yellow  pilosity  ; 
abdomen  with  rounded,  dorso-central,  opaque  black  spot  on  basal  four 

segments hccmatopotum,  p.  62. 

Stripes  on  scutum  slightly  curved;  scutellum  with  very  indistinct, 
sparse,  yellow  pilosity;  abdomen  with  bases  of  all  segments  opaque 
velvety  black  and  apices  with  whitish  pollinosity quadnvittatum,  p.  61. 

Simulium  quadrivittatum  Loew. 

Female. — Black.  Frons  and  face  thickly  covered  with  bluish-white 
pollinosity;  antennae  yellow,  distinctly  browned  from  fourth  joint  to 
apex;  palpi  brown-black.  Scutum  velvety,  opaque  black;  two  bluish- 
Avhite,  slightly  iridescent,  pollinose  stripes  on  the  dorsum,  which  are 
slightly  dilated  anteriorly  and  a  little  curved;  posterior  margin  of 
scutum,  and  lateral  margins,  as  well  as  prescutum,  similarly  polli- 
nose; pleurae  with  bluish- white  pollen;  scutellum  opaque  black; 
postscutum  with  iridescent  pollen.  Abdomen  black;  basal  four  seg- 
ments opaque,  with  bluish-white  pollinosity  on  first  segment  below 
basal  scale  and  on  the  posterior  lateral  margins  of  next  three ;  apical 
four  segments  glossy  black.  Legs  black-brown,  yellowish  as  follows : 
Bases  of  all  tibiae;  mid  tarsi  except  apices  of  joints  and  last  joint; 
hind  tarsi  except  apices  of  joints  1-3.  Bases  of  all  tibiae  and  of  first 
hind  tarsal  joint  silvery.  Wings  clear,  basal  veins  brown,  thick 
veins  yellow,  thin  veins  colorless.     Halteres  yellow,  stalk  black-brown. 

Frons  slightly  divergent-sided,  not  one-third  the  head  width  at 
upper  angle  of  eyes,  almost  bare  of  hairs ;  face  one-third  longer  than 


62  AMERICAN"   BLACK   FLIES   OR  BUFFALO   GNATS. 

wide,  surface  hairs  very  weak  and  sparse;  hairs  on  palpi  brown; 
postocular  cilia  brown.  Scutum  with  yellow,  hairlike  pilosity; 
pleural  tuft  brown,  very  weak;  scutellum  with  upright  brown  hairs. 
Basal  fringe  of  abdomen  brownish-yellow,  surface  hairs  on  segments 
brown,  weak,  except  at  apex  where  they  become  distinctly  longer. 
Legs  with  brownish-yellow  pilosity  and  scattered,  longer  upright, 
brown  dorsal  hairs;  fore  tarsi  not  dilated,  first  and  third  joints  with 
paired  apical  hairs;  claws  simple.  Cross- vein  on  wing  but  little 
beyond  middle  of  subcosta ;  basal  hairs  on  wing  and  short  bristles  on 
thick  veins  brown. 

Length,  2  mm. 

This  species  was  originally  described  from  Cuba  and  is  represented 
in  the  collection  by  specimens  from  Cayamas,  Cuba  (E.  A.  Schwarz)  ; 
La  Palma,  Costa  Rica  (Biolley)  ;  and  Utuado,  Porto  Kico,  marked 
"biting  flies"  (C.  W.  Richmond).  There  is  also  a  large  series  of 
specimens  from  Trinidad  River  and  Cabima,  Panama,  May,  1911 
(Busck),  which  agree  with  the  Cuban  specimens,  except  that  the 
thoracic  stripes  are  less  distinct  and  the  specimens  average  rather 
less  in  size  and  are  darker  in  color. 

Nothing  is  known  of  the  early  stages  of  this  species,  and  the  male 
is  also  unknown. 

Simulium  haematopotum,  new  species. 

Female. — Black.  Frons  and  face  with  shining  pearlaceous  pol- 
linosity. Antenna?  yellow,  browned  from  fourth  joint  to  tip;  palpi 
brown,  paler  at  base.  Scutum  velvety  black,  with  two  broad  pear- 
laceous stripes,  which  are  broader  at  anterior  ends  than  the  black 
space  between  them,  taper  slightly  posteriorly,  but  are  uncurved; 
posterior  and  lateral  margins  similarly  pollinose;  pleura?  shining 
black,  with  more  or  less  distinct  pearlaceous  pollinosity;  scutellum 
brown;  postscutum  with  pearlaceous  pollinosity.  Abdomen  brown- 
ish; opaque  on  basal  four  segments,  each  of  which  has  a  rounded, 
opaque,  black  dorsal,  and  a  less  distinct  lateral  spot,  posterior  margins 
of  these  segments  whitish  dusted ;  apical  four  segments  with  dorsal 
portions  shining;  the  fifth  segment  with  a  rounded  dorsal  spot,  the 
others  almost  entirely  black.  Legs  yellow,  black  as  follows:  Mid 
and  hind  coxa?;  fore  tarsi;  apices  of  first  four  and  all  apical  joints 
of  mid  tarsi ;  femora  except  bases,  apical  half  of  tibia?,  apical  halves 
of  joints  1-3,  and  all  last  two  joints  of  tarsi  of  hind  legs.  Wings 
clear,  basal  and  thick  veins  yellow.    TTalteres  yellow,  stalk  blackened. 

Frons  slightly  divergent-sided,  less  than  one-third  the  head 
width  at  upper  angle  of  eyes,  surface  hairs  weak,  brownish  yellow; 
face  as  long  as  frons  and  one-half  longer  than  broad,  haired  as  frons; 
hairs  on  palpi  brown;  postocular  cilia  brown.  Scutum  with  close- 
lying,  golden  yellow,  hairlike  pilosity;  pleural  tuft  brownish  yellow; 


SIMULIUM.  63 

scutellum  with  closely  placed  yellow  pilosity,  and  brownish,  upright, 
longer  hairs.  Abdominal  basal  fringe  short,  yellow;  segments  of 
abdomen  with  short,  sparse,  yellow  hairs,  and  longer,  dark  hairs  at 
apex.  Legs  with  pale  yellowish  pilosity,  which  is  whitish  at  bases 
of  tibiae  and  on  basal  joint  of  hind  tarsi ;  dorsal  surfaces  with  longer, 
blackish,  upright  hairs;  fore  tarsi  slightly  dilated,  the  paired  apical 
hairs  present  on  joints  1  and  3;  claws  simple.  Wings  with  brown 
hairs  at  base  and  brown  surface  hairs  on  thick  veins;  cross-vein  at 
two-fifths  from  end  of  subcosta. 

Length,  1.5-2  mm. 

Type.— Cat.  No.  15414  U.  S.  National  Museum. 

Locality. — Santa  Lucrecia,  Vera  Cruz,  Mexico  (F.  W.  Urich). 
There  is  also  a  specimen  from  Cayamas,  Cuba  (E.  A.  Schwarz) 
which  evidently  belongs  to  this  species. 

The  series  taken  by  F.  W.  Urich  is  labeled  "  Bloodsucking,  man, 
October,  1911." 

The  early  stages  and  the  male  are  unknown. 

ADDENDA. 

When  the  manuscript  of  this  paper  was  under  preparation  I  had 
considerable  doubt  as  to  whether  there  were  not  several  closely  allied 
forms  confused  under  certain  specific  names,  this  being  particularly 
the  case  with  meridionale.  That  size  can  not  always  be  accepted  as  a 
safe  guide  to  the  separation  of  species  is  abundantly  evident  to  any 
student  of  insects,  and  although  in  the  series  of  specimens  in  the  Na- 
tional Museum  collection  there  was  much  disparity  in  this  respect, 
the  specimens  presented  no  tangible  characters  which,  without  the 
confirmatory  evidence  provided  by  a  knowledge  of  the  early  stages, 
might  be  accepted  as  of  specific  value.  Thus  I  left  under  one  name 
at  least  three  forms  which  may  in  the  larval  and  pupal  stages  prove 
to  be  very  dissimilar.  The  distinctions  in  the  adults  are  very  minute 
in  the  genus  Simulium  and  are  hardly  appreciable  to  anyone  unac- 
quainted with  the  family.  I  am  therefore  pleased  to  have  had  access 
to  the  material  belonging  to  the  Illinois  State  Laboratory  of  Natural 
History  because  of  the  additional  light  the  material  representing  the 
early  stages  therein  contained  has  cast  upon  the  question  of  the  num- 
ber of  species  in  the  meridionale  group.  Prof.  S.  A.  Forbes  has  kindly 
given  me  permission  to  include  the  matter  in  this  addenda  as  part 
of  my  paper. 

Simulium  forbesi,  new  species. 

Female. — Black,  covered  with  a  pale-gray  pollinosity,  which  gives 
to  the  insect  a  pale-gray  appearance.  Antennas  and  palpi  black,  the 
former  rarely  slightly  paler  at  bases.  Scutum  with  three  black  vittae, 
the  central  one  narrow,  the  outer  pair  broader,  more  or  less  distinctly 


64  AMERICAN   BLACK   FLIES   OR  BUFFALO    GNATS. 

curved  outward  at  anterior  extremity,  and  convex  on  the  posterior 
half;  pleurae  gray  pollinose,  scutellum  and  postscutellum  gray  polli- 
nose.  Basal  abdominal  scale  gray  and  next  three  segments  broadly 
black-brown,  opaque,  on  dorsum,  lateral  margins  gray  pollinose,  next 
segment  more  narrowly  blackened  on  dorsum,  the  lateral  margins  and 
remaining  segments  gray  pollinose.  Legs  black;  generally  only  the 
bases  of  tibiae  yellow^  but  occasionally,  in  immature  specimens,  the 
black  color  is  confined  to  the  apices  of  femora,  bases  and  apices  of 
tibiae,  and  apices  of  tarsal  joints.    Wings  clear.    Halteres  yellow. 

Frons  at  upper  angle  barely  more  than  one-fifth  the. head  width, 
slightly  converging  toward  antennae,  the  surface  with  short,  white, 
decumbent  pilosity ;  face  distinctly  wider  than  widest  part  of  frons, 
and  longer  than  wide,  the  surface  with  pilosity  similar  to  that  on 
frons;  antennal  pile  short  and  inconspicuous,  whitish;  palpi  with 
short  whitish  pile.  Scutum  with  closely  placed  pilosity  which  is  hair- 
like, yellowish  white  in  color,  and  adheres  closely  to  surface,  becom- 
ing slightly  longer,  but  not  upright,  posteriorly ;  scutellum  with  much 
longer  pilosity,  which  is  concolorous  with  that  on  scutum  and  upright 
on  margin;  pleural  tuft  whitish,  postspiracular  area  bare.  Basal 
abdominal  scale  with  pale  fringe ;  the  hairs  on  segments  of  abdomen 
short  and  pale.  Legs  normal  in  shape ;  fore  tarsi  very  slightly  thick- 
ened, the  apical,  paired  hairs  not  distinguishable;  hind  tarsi  with 
distinct  scale  and  dorsal  excision  on  second  joint;  claws  bifid;  surface 
of  all  legs  with  pale  hairs,  which  are  most  conspicuous  on  the  tibiae, 
giving  them  a  whitish  appearance. 

Male. — Deep  black,  opaque.  Face  silvery  pollinose;  antennae  and 
palpi  black.  Scutum  with  rarely  a  slight  silvery  pollinosity  poste- 
riorly and  on  the  lateral  margins,  and  otherwise  velvet}^  black; 
pleurae  slightly  covered  with  white  pollinosity;  scutellum  velvety 
black ;  postscutum  slightly  pollinose,  glossy.  Abdomen  velvety  black, 
only  the  venter  yellowish,  no  silvering  noticeable  on  any  of  the  speci- 
mens before  me;  hairs  on  surface  short,  yellowish.  Legs  colored  as 
in  (he  female,  surface  hairs  yellow,  with  an  admixture  of  longer 
brown  upright  hairs  on  the  dorsal  surfaces.  Wings  clear,  veins  pale 
yellowish,  the  thin  veins  very  indistinct.     Halteres  brown. 

The  head  is  formed  as  in  other  species  of  this  genus,  the  upper  eye 
facets  being  conspicuously  enlarged  while  the  lower  half  of  the  eye 
has  small  facets.  The  scutum  is  thickly  covered  with  pile,  which  is 
golden  yellow  in  color  and  rather  more  scalelike  than  that  of  the 
male;  there  are  no  upright  hairs  on  disk,  and  posteriorly  the  pilosity 
i  decumbent  as  in  the  female;  scutellum  with  yellowish  pile  and 
upright  brownish  hairs  on  margin.  Basal  fringe  of  abdomen  brown 
isli.  the  surface  hairs  also  brown.  Fore  tarsus  slender;  hind  tarsus 
only  slightly  dilated;  apical  paired  hairs  absent  from  fore  tarsus,  or 


SIMULIUM.  65 

indistinguishable,  hind  tarsus  formed  as  in  female;  olaws  trifid. 
Wings  normal. 

Length,  2-2.5  mm. 

Type. — Locality,  Illinois  River,  at  Havana.  A  very  large  number 
of  both  sexes  were  taken,  many  of  them  reared  from  pupae  which 
were  found  in  the  river.     A  description  of  the  pupa  follows. 

Pupa. — Yellow,  becoming  brown  before  emergence  of  the  imago, 
the  colors  of  which  may  be  distinctly  traced  through  the  body  wall 
of  the  pupa  some  time  before  it  is  ready  to  emerge.  The  respiratory 
organs  branch  near  the  base,  generally  into  three  main  stems,  the 
branch  or  stem  which  is  directed  anteriorly  again  breaking  into  two 
stems  which  are  bifid  from  near  their  bases ;  the  central  stem  is  again 
subdivided  into  three  smaller  branches,  the  central  one  ending  in 
2  filaments  and  the  other  two  in  4  each;  the  posteriorly  directed 
branch  generally  divides  at  near  to  the  base,  a  further  subdivision 
taking  place  a  little  farther  up,  each  of  the  latter  branches  generally 
having  2  filaments,  making  as  a  rule  from  22  to  24  or  25  filaments  in 
all.  The  abdomen  has  on  the  fourth  and  fifth  segments  (counting 
the  segment  showing  just  behind  the  scutellum  as  the  first)  a  trans- 
verse row  of  four  short  hooks,  the  points  of  which  are  turned  ceph- 
alad ;  on  each  side  of  the  dorsal  line,  a  somewhat  similar  series  on  the 
eighth  segment  which  are  more  numerous,  smaller,  and  almost  con- 
nected in  center ;  on  the  ninth  segment  the  row  is  almost  continuous 
on  the  posterior  margin  of  the  segment.  The  fifth,  sixth,  seventh, 
and  eighth  ventral  segments  have  each  two  hooks  on  each  side  which 
are  much  closer,  in  each  pair,  to  each  other  than  the  transverse  space 
between  the  pairs. 

Length,  3-3.5  mm. 

The  cocoon,  which  is  generally  attached  to  stems  of  plants  or  to 
posts  in  the  stream,  is  very  similar  to  that  of  johannseni. 

The  type  and  paratypes  of  this  species  are  in  the  Illinois  State  Lab- 
oratory of  Natural  History. 

I  have  much  pleasure  in  dedicating  this  species  to  Dr.  Stephen  A. 
Forbes,  who  has  done  so  much  to  elucidate  questions  in  connection 
with  this  group  on  the  Illinois  River. 

Simulium  johannseni  Hart. 

This  species  is  very  clearly  described  by  Hart  in  the  Twenty- 
seventh  Report  of  the  State  Entomologist  of  Illinois,  1912,  page  32. 
It  is  only  necessary  for  me  to  point  out  that  the  male  has  the  three 
vittse  on  the  scutum  generally  distinct  and  the  pilosity  whitish.  The 
color  of  the  legs  in  both  species  is  as  given  in  the  description  here- 
with for  forbesi,  although  in  alcoholic  specimens  the  color  is  as  fig- 
ured by  Hart  in  his  original  description.     Fresh  females  of  johannseni 

16125°— 14 5 


66  AMERICAN  BLACK  FLIES  OR  BUFFALO  GNATS. 

have  the  dorsolateral  stripes  generally  discontinued  before  the  an- 
terior margin  and  not  outwardly  curved,  as  well  as  the  central  line 
extremely  narrow;  the  pilosity  over  the  whole  insect  is  longer  than 
in  forbesi  and  conspicuously  so  on  the  abdomen ;  the  marking  on  the 
abdomen  is  usually  confined  to  a  series  of  spots,  one  on  each  side  of 
the  first  four  segments  exclusive  of  the  basal  scale.  The  species  is 
also  noticeably  larger  than  either  forbesi  or  meridionale,  being  3-4 
mm.  in  length. 

For  description  of  larva  and  pupa  see  Hart's  paper  above  men- 
tioned. 

It  is  possible  that  the  larger  specimens  mentioned  as  in  the  U.  S. 
National  Museum  collection  under  meridionale  are  really  this  species, 
but  I  have  no  means  of  determining  that  question  at  present. 

So  far  as  my  material  permits  me  to  judge,  johannseni  occurs  at 
Havana,  111.,  till  the  end  of  May,  when  its  place  is  taken  by  forbesi, 
which  is  equally  abundant. 

Simulium  meridionale  Riley  and  its  allies. 

The  three  species  which  I  at  present  recognize  as  belonging  to  this 
group  are  meridionale  Riley,  johannseni  Hart,  and  forbesi  new 
species. 

The  pupal  stages  of  these  three  species,  which  are  very  closely 
allied  in  the  adult  stage,  are  very  distinct  and  may  be  readily  sep- 
arated from  one  another  by  the  number  of  pupal  respiratory  filaments. 
In  johannseni  these  are  4  in  number,  in  meridionale  6,  and  in  forbesi 
generally  24  or  25,  although,  as  is  the  case  when  a  large  number  of 
filaments  are  present,  there  may  be  a  slight  variation  in  the  total 
number  in  individual  specimens.  Johannseni  is  the  only  species 
which  I  have  seen  with  four  pupal  filaments,  although  bracteatwn  has 
been  recorded  by  Strickland  as  possessing  this  number  also.  I  have 
not  seen  Strickland's  material,  so  can  not  confirm  the  identification. 

The  adult  females  of  this  group  of  species  may  be  readily  distin- 
guished from  other  North  American  forms  by  their  possession  of  the 
following  combination  of  characters:  Scutum  with  three  vittae,  the 
submedian  pair  curved;  the  pilosity  hairlike  on  scutum;  abdomen 
more  or  less  distinctly  spotted  on  middle  of  each  dorsal  segment ;  legs 
generally  almost  unicolorous,  rarely  distinctly  bicolored  (in  alcoholic 
specimens  this  bicoloring  is  conspicuous  in  the  case  of  johannseni)  ; 
claws  bifid.  The  males  are  not  so  readily  separated,  but  I  have  im 
serted  them  in  mv  synoptic  key,  by  means  of  which  I  believe  they  may 
be  readily  locate* I. 

From  the  data  gathered  in  the  field  work  on  (his  group  in  the 
Illinois  River  region,  near  Havana,  it  is  evident  that  johannseni, 
although  a  pest  owing  to  the  great  numbers  in  which  it  occurs,  does 


SIMULIUM.  67 

not  appear  to  be  guilty  of  biting  man.  It  has,  on  the  other  hand, 
been  clearly  proven  that  forbesi  is  given  to  attacking  man  and  also 
stock.  As  it  occurs  in  great  numbers  there  is  a  possibility  of  its 
doing  considerable  damage,  although  as  a  general  rule  it  is  not  very 
troublesome  away  from  the  river.  Mr.  C.  A.  Hart  has  found  speci- 
mens of  Simulium  forbesi  in  Mason  County,  over  5  miles  southeast  of 
Havana.  As  the  nearest  possible  breeding  place  of  the  species  is  the 
Illinois  River,  it  is  evident  that  the  species  can  fly  for  a  considerable 
distance.  As  there  was  no  appreciable  diminution  in  the  numbers 
of  the  species  at  this  distance  it  was  quite  clear  that  these  were  not 
merely  accidental  stragglers,  whose  presence  was  due  to  their  being 
carried  by  stock  or  otherwise,  and  that  the  ditches,  which  are  very 
small  in  that  vicinity  and  never  present  favorable  breeding  quarters 
at  any  time,  could  not  possibly  have  stocked  the  country  so  thoroughly 
with  the  insects.  No  extended  investigations  were  carried  out  to  dis- 
cover the  extent  of  the  area  covered  by  the  species,  but  according  to 
reports  obtained,  and  which  there  is  no  reason  to  discredit,  the  range 
of  the  species  was  considerably  wider  than  ascertained  by  Mr.  Hart. 
No  evidence  has  been  discovered  to  prove  that  johannseni  or  forbesi 
live  in  the  larval  stage  in  ditches  such  as  are  present  in  the  part  of 
Mason  County  above  referred  to. 

It  may  be  of  interest  to  mention  that  the  agents  of  the  Illinois  State 
Laboratory  of  Natural  History  have  found  the  parasites  mentioned 
by  Strickland  commonly  in  Simulium  larvae  in  both  the  Illinois  River 
and  the  Sangamon  River  at  near  the  source  of  the  latter.  So  far  as 
the  records  indicate,  vittatum  was  the  only  species  affected,  but  the 
percentage  of  parasitized  individuals  was  very  large. 

In  the  records  of  the  work  done  by  agents  of  the  Bureau  of  Ento- 
mology many  years  ago  there  occurs  a  note  on  these  parasites,  but  the 
fact  was  not  mentioned  in  any  of  the  published  reports  on  the  family. 


CATALOGUE  OF  NORTH  AMERICAN  AND  CENTRAL  AMERICAN 

SIMULIID^. 

[°  Types   in   United   States   National   Museum ;    b  Represented   in    United   States   National 

Museum.] 

Prosimulium  Roubaud.     Comptes-Rendus  Acad.  Sci.,  Paris,  1906,  pp.  519-521. 
a  pleurale  Malloch.    This  paper,  p.  17. 
6  hirtipes  Fries.     Monogr.   Simulium,  1824,  no.  17. 

pecuarum  Garman  (not  Riley).     Bui.  159,  Ky.  Agr.  Exp.    Sta.,  1912, 
p.  18. 
a  fulvum  Coquillett.     Proc.  U.  S.  Nat.  Mus.,  vol.  25, 1903,  p.  96. 

ochraceum  Coquillett  (not  Walker).     Proc.  Wash.  Acad.  Sci.,.  vol.  2, 
1900,  p.  393. 
a  pecuarum  Riley.     Rept.  U.  S.  Dept.  Agr.  f.  1886  (1887),  p.  512. 
a  mutatum  Malloch.    This  paper,  p.  20. 
Parasimulium  Malloch.     This  paper,  p.  24. 
°  furca^um  Malloch.    This  paper,  p.  24. 
Simulium  Latreille.     Hist.  Nat.  Crust.  Ins.,  vol.  3,  1802,  p.  426. 
a  aureopunctatum  Malloch.    This  paper,  p.  27. 
6  subnigrum  Lutz.     Mem.  Inst.  Oswaldo  Cruz,  vol.  2,  part  2,  p.  239. 

■  hippovorum  Malloch.     This  paper,  p.  28. 

b  ochraceum  Walker.     Trans.  Ent.  Soc.  Lond.,  vol.  5,  1S61,  p.  332. 
6  notatum  Adams.     Kans.  Univ.  Sci.  Bui.,  vol.  2,  1904,  p.  434. 
°bivittatum  Malloch.    This  paper,  p.  31. 
°  trivittatum  Malloch.     This  paper,  p.  30. 

■  distinctum  Malloch.  Proc.  Ent.  Soc.  Wash.,  vol.  15,  1913,  p.  133. 

b  pictipes  Hagen.     Proc.  Bost.  Soc.  Nat.  Hist.,  vol.  20,  1879,  p.  305. 

innoxium  Comstock.     Manual  for  the  Study  of  Insects,  1895,  p.  452. 
°  virgatum  Coquillett.     Proc.  U.  S.  Nat.  Mus.,  vol.  25,  1903,  p.  97. 
°griseum  Coquillett.     Bui.  10,  new  ser.,  Div.  Ent.,  U.  S.  Dept.  Agr.,  1898. 

p.  69. 
6  vittatum  Zetterstedt.     Ins.  Lappon.,  1840,  p.  803. 

argus  Williston.     Bui.  7,  Div.  Orn.   and  Mamm.,  U.   S.   Dept.   Agr., 
1893,  p.  253. 

f  decorum  Walker.     List  Dipt.  Brit.  Mus.,  vol.  1,  1848,  p.  112. 

minutum    Lugger.     Bui.    48,    Minn.    Agr.    Exp.    Sta.,    1896,    p.    202. 
(Johannsen.) 
forbesi  Malloch.     This  paper,  p.  63. 
"meridionale  Riley.     Rept.  U.  S.  Dept.  Agr.  f.  1886  (1887),  p.  513. 

occidental  Townsend.  (?)    Psyche,  1891,  p.  107. 
johannseni  Hart.  27th  Rept.  State  Ent.  111.,  1912,  p.  42. 
tamaulipense.  Townsend.     Journ.  N.  Y.  Ent.  Soc,  vol.  5,  1898,  p.  171. 
n  hunteri  Malloch.     This  paper,  p.  59. 
6venustum  Say.     Jouru.  Acad.  Sci.  Phila.,  vol.  8,  1S29.  p.  28. 

venustoides  Hart.     (Female.)     27th  Rept.  State  Ent.  111.,  1912,  p.  42. 
ajenningsi  Malloch.     This  paper,  p.  41. 

venu.stum  var.  a  Johannsen.     Bui.  68,  N.  Y.  State  Mus.,  1903,  p.  381. 


PAPERS    ON    SIMULIID^.  69 

Simulium  Latreille — Continued. 

aparnassum  Mallocb.     This  paper,  p.  30. 

°  arcticum  Malloch.     This  paper,  p.  37. 

0  clavipes  Malloch.     This  paper,  p.  40. 

tarsale  Williston.     Trans.  Ent.  Soc.  Lond.,  1896,  p.  268. 

pulchrum  Johannsen  (not  Philippi).     Bui.  08.  N.  Y.  State  Mus.,  1003, 
p.  37G. 
6exiguum  Roubaud.     Bui.  Mus.  Paris,  1906,  p.  109. 
6  metallicum  Bellardi.     Saggio  Ditter.  Mess.,  1859,  vol.  1,  p.  14. 
6  mexicanum  Bellardi.     Saggio  Ditter.  Mess,  app.,  1861-62,  p.  6. 
a  bracteatum  Coquillett.     Bui.  10,  new  ser.,  Div.  Ent,  U.  S.  Dept.  Agr.,  1898, 

p.  69. 
a  piscicidium  Riley.     Amer.  Ent.,  vol.  2,  1870,  p.  367. 

venustoides  Hart,  27th  Rept.  State  Ent.  111.,  1912,  p.  42. 
tephrodes  Speiser.     Ins.  Borse,  1904,  p.  148. 

cinereum  Bellardi.     Saggio  Ditter.  Mess.,  vol.  1,  1859,  p.  13.     Pre- 
occupied name. 
6  quadrivittatum  Loew.     Dipt.  Amer.  Sept.  Ind.,  Cent.  2,  species  2. 
°  haematopotum  Malloch.    This  paper,  p.  62. 
a  glaucum  Coquillett.     Proc.  U.  S.  Nat.  Mus.,  1903,  vol.  25,  p.  97. 

UNBECOGNIZABLE    SPECIES. 

Similium  irritatum  Lugger.    2d  Rept.  Ent.  Minn.,  1896,  p.  177. 
Simulium  invenustum  Walker.    List  Dipt.  Brit.  Mus.,  vol.  1,  1848,  p.  112. 
Simulium  molestum  Harris.    Ins.  Inj.  Veg.,  3d  ed.,  1862,  p.  601. 
Simulium  tribulatum  Lugger.     2d  Rept.   Ent.  Minn.,  1896,  p.  205.     Johannsen 
gives  it  as  probably  a  synonym  of  vittatum  Zett. 

A   LIST   OF   THE   PRINCIPAL   PAPERS   DEALING   WITH   THE   LIFE 
HISTORIES  OF  AMERICAN  SIMULIIDiE. 

J  870.     Osten    Sacken,    C.    R. — On   the   transformations   of   Simulium.K Amer. 

Ent.  and  Bot,  vol.  2,  pp.  229-331. 
1880.     Hagen,  H.  A. — A  new  species  of  Simulium  with  a  remarkable  nymphal 

case. < Proc.  Bost.  Soc.  Nat.  Hist,  vol.  20,  pp.  305-307. 
1880.     Barnard,  W.  S. — Notes  on  the  development  of  a  black  fly   (Simulium) 

common  in  the'  rapids  around  Ithaca,  N  Y.<Amer.  Ent,  vol.  3,  pp. 

191-193. 
1883.     Hagen,  H.   A. — Simulium  feeding  on  chrysalides. < Ent.   Monthl.   Mag., 

vol.  19,  pp.  254-255. 

1885.  Riley,  C.  V. — The  southern  buffalo  gnat   (Simulium  sp.).<Rept.  Ent., 

U.  S.  Dept.  Agr.  f.  1884,  pp.  340-345. 

1886.  Doran,  E.  W. — The  buffalo  gnat.  <  Rept.  on  Econ.  Ent.  of  Tenn.  to  the 

Bureau  of  Agr.  Stat.,  Mines,  and  Immigr.,  pp.  239-242. 

1887.  Webster,   F.   M.— Report  on  buffalo   gnats.<Bul.   14,   Div.   Ent,   U.    S. 

Dept.  Agr.,  pp.  29-39. 
1887.     Riley,  C.  V.— Buffalo  gnats. <Repts.  Ent.,  U.  S.  Dept.  Agr.  f.  1886,  pp. 

492-517. 
1889.     Webster,   F.  M. — Simulium  or  Buffalo  gnats.  <  Rept.   Bur.  Anim.   Ind., 

U.  S.  Dept.  Agr.  f.  1887  (1889),  pp.  456-^65. 
1892.     Webster,   F.   M. — Buffalo   gnats    (Simuliidse)    in   Indiana   and   Illinois, 

Proc.  Ind.  Acad.  Sci.,  December,  1892,  pp.  155-159. 


70  AMERICAN  BLACK  FLIES  OR  BUFFALO  GNATS. 

1895.  Town  send,  C.  H.  T. — On  the  correlation  of  habit  in  nemocerous  and 
brachycerous  Diptera  between  aquatic  larvae  and  bloodsucking  adult 
females.  <Journ.  N.  Y.  Ent.  Soc,  vol.  3,  pp.  134-136. 

1895.  Miall,  L.   C. — The  natural  history  of  aquatic  insects.     Simulium,  pp. 

175-188. 

1896.  Lugger,  O. — Buffalo  gnats,  black  flies.  < 2nd  Ann.  Rept.  Ent.  State  Exp. 

Sta.,  Univ.  Minn.,  pp.  172-182. 
1896.     Osborn,  H. — Insects  affecting  domestic  animals. <Bul.  5,  new  ser.,  Div. 

Ent.,  U.  S.  Dept.  Agr.,  pp.  31-58. 
1901.     Kellogg,  V.  L. — Food  of  larvae  of  Simulium  and  B lepharocera.< Psyche, 

vol.  9,  pp.  166-167. 

1901.  Needham,  J.  G.,  and  Betten,  C. — Aquatic  insects  of  the  Adirondacks. 

<Bul.  47,  N.  Y.  State  Mus.,  pp.  393,  407-408,  574. 

1902.  Taylor,  T.  H. — On  the  tracheal  system  of  Simulium.<Tnms.  Ent.  Soc. 

Lond.,  1902,  pp.  701-716. 

1903.  Johannsen,  O.  A. — Aquatic  nematocerous  diptera. < Aquatic  Insects  in 

New  York  State,  pt.  6,  Bui.  68,  N.  Y.  State  Mus.,  pp.  336-388. 

1904.  Webster,  F.  M. — The  suppression  and  control  of  the  plague  of  gnats  in 

the  valley  of  the  lower  Mississippi  River,  and  the  relation  thereto  of 
the  present  levee  system,  irrigation  in  the  arid  West,  and  tile  drainage 
in  the  Middle  West.<Proc.  25th  Ann.  Meet.  Soc.  Prom.  Agr.  Sci., 
pp.  53-72. 

1905.  Headlee,  T.  J. — Blood  gills  of  Simulium  pictipes.  <Amer.  Nat.,  vol.  41, 

pp.  875-885. 

1909.  Lutz,  Dr.  A. — Brazilian  Simuliidse.OIeni.  Inst.  Oswaldo  Cruz,  vol.  1, 

pt.  2,  pp.  124-146. 

1910.  Lutz,  Dr.  A. — Brazilian  Simuliidae.<Mem.  Inst.  Oswaldo  Cruz,  vol.  2, 

pt.  2,  pp.  213-262. 
1910.     Strickland,  E.  H. — Some  parasites  of  Simulium  larvae  and  their  effects 

on  the  development  of  the  host.<Biol.  Bui.,  vol.  21,  no.  5,  October, 

1911,  pp.  302-334. 
1912.     Garman,    H. — A    preliminary    study    of    Kentucky    localities    in    which 

pellagra  is  prevalent. <Bul.  159,  Ky.  Agr.  Exp.  Sta.  . 

1912.  Forbes,    S.    A. — Black-flies   and   buffalo-gnats    (Simuliu7n)    as   possible 

carriers  of  pellagra  in  Illinois. <27th  Rept.  State  Ent.  111.,  pp.  21-55. 

1913.  Strickland,  E.  H. — Further  observations  on  the  parasites  of  Simulium 

larvae.    Journ.  Morph.,  Phil.,  vol.  24,  p.  43. 


INDEX  TO  GENERA  AND  SPECIES. 


[Pages  on  which  genera  and  species  are  described  are  given  in  black-faced  type.] 


Page. 

argus  (Simulium) 13,  55 

arcticum  (Simulium) 34,  37 

Atractocera 12 

aureopunctatum  (Simulium) 27 

aureum  (Simulium) 21 

bivittatum  (Simulium) 29,  31 

bracteatum  (Simulium) 15,  25,  34,  38 

cinereum  (Simulium) 13,  26,  29 

clavipes  (Simulium) 34,  40 

colombaschense  (Simulium) 12 

colombaschensis  (Simulium) 11 

columbaczense  (Simulium) 7, 12 

decorum  (Simulium) 13 

distinctum  (Simulium) 25,  29,  30 

Eusimulium 21 

exiguum  (Simulium) 13, 14,  34,  39 

forbesi 15,  25,  47,  63 

fulvum  (Prosimulium) 17, 18 

furcatum  (Parasimulium) 24 

glaucum  (Simulium) 26,  60 

griseum  (Simulium) 25,  47,  52 


haematopotum  (Simulium) .  . 

61,62 

hippovorum  (Simulium) 

27,28 

hirtipes  (Simulium) 9, 10 

14,15 

17,18 

hunteri  (Simulium) 

48,59 

innoxium  (Simulium) 

68 

invenustum  (Simulium) .... 

13 

irritatum  (Simulium) 

13 

jenningsi  (Simulium) 

14,  25,  34,  41 

johannseni  (Simulium) ...  15 

25,34 

47,65 

lineatum  (Simulium) 

27 

lutzi  (Simulium) 

14 

maculatum 

12 

Melusina 

12 

meridionale  (Simulium)  14, 15,47,  49,51,  66 


Page. 

metallicum  (Simulium) 26,  47,  48 

mexicanum  (Simulium) 26,  34,  35 

minutum  (Simulium) 13, 14 

molestum  (Simulium) 69 

mutatum  (Prosimulium) 17,  20 

notatum  (Simulium) 25,  29,  32 

occidentale  (Simulium) 50 

ochraceum  (Simulium) 13,  29,  30 

Parasimulium 14,  24 

parnassum  (Simulium) 34,  36 

pecuarum  (Prosimulium) 9, 13, 

14, 15, 17, 21 
pictipes  (Simulium) ...  8, 10, 14,  26,  48,  55 

piscicidium  (Simulium) 14,  34,  45 

pleurale  (Prosimulium) 17 

Prosimulium 9, 14, 15 

pulchrum  (Simulium) 13 

quadrivittatum  (Simulium) 61 

regelationis ., 12 

reptans  (Simulium) 12, 13,  27,  34 

Simulium.  11,14,21,25,26,29,34,47,61,63 

subnigrum  (Simulium) 27 

tamaulipense  (Simulium) 51 

tarsale(  Simulium) 13,  34,  46 

tephrodes  (Simulium) 69 

Tipula 12 

tribulatum  (Simulium) 55 

Trichocera 12 

trivittatum  (Simulium) 29,  30 

venustoides  (Simulium) 46 

venustum  (Simulium) 8, 10, 

14, 15,  26,  34,  43 

venustum  var.  a  (Simulium) 42,  45 

virgatum  (Simulium) 26,  48,  57 

vittatum 13, 14, 15,  26,  4S  53 

71 


Plate  I. 
ANATOMICAL  DETAILS  AND  WING  VENATION  OF  SIMULIID.E. 

Fig.  1. — Lateral  view  of  thorax  of  Prosimulium  pleurale:  nx,  Pronotum;  psc*, 
proscutum ;  set-,  scutum ;  sch,  scutellum ;  pn2,  inesothoracic  post- 
notum;  n3,  metanotum ;  pn3,  metathoracic  postnotum;  pph,  post- 
phragma ;  w,  wing ;  h,  haltere ;  spi  2,  prothoracic  and  mesothoracic 
spiracles;  epsx  2  3,  prothoracic,  mesothoracic,  and  metathoracic  epi- 
sterna ;  epnu  2  3,  prothoracic,  mesothoracic,  and  metathoracic  epi- 
mera;  m,  membranous  area;  ps123,  prothoracic,  mesothoracic,  and 
metathoracic  sutures;  wp2  3,  pleural  wing  sutures;  ppt,  postparap- 
terum  ;  s2,  divided  mesosternum ;  czi  2  3,  coxae ;  abs,  abdominal  basal 
scale.  The  pleural  tuft  occupies  the  area  covered  by  the  letters  ppt 
and  icp3  in  figure. 
2. — Wing  of  Simulium:  A,  humeral  vein;  B,  costa ;  C,  subcosta ;  D,  first 
longitudinal  vein;  E,  upper  branch  of  radius  or  third  longitudinal 
vein;  F,  lower  branch  of  radius;  G,  fourth  longitudinal  vein  or 
medius;  H,  fold  which  has  been  sometimes  considered  as  the  cubi- 
tus; J,  cubitus  or  fifth  longitudinal  vein;  in  cases  where  the  fold 
has  been  reckoned  as  the  cubitus  this  vein  has  been  named  the  anal 
vein. 
3. — Wing  of  Prosimulium.  (Explanation  as  in  fig.  2.) 
4. — Wing  of  Parasimulium.     (Explanation  as  in  fig.  2.)      (Original.) 

72 


Tech.  Series  26,  Bureau  of  Entomology,  U.  S.  Dept.  of  Agriculture 


Plate  I. 


2 
o 

z 
< 


16125°— 14 6 


Plate  II. 
LEGS  AND  TARSAL  CLAWS  OF  SIMULIIDJE. 

Fig.    1. — Hind  femur,  tibia,  and  two  basal  tarsal  joints  of  Prosimulium  fulvum, 
male. 

2. — Same  of  Prosimulium  pecuarum,  female. 

3. — Claw  of  Simulium  hunteri,  female. 

4. — Claw  of  Simulium  arcticum,  female. 

5. — (Maw  of  Simulium  clavipes,  female. 

6. — Claw  of  Simulium  mexicanum,  female. 

7. — Claw  of  Simulium  venustum,  female. 

8. — Claw  of  Simulium  parnassum,  female. 

9. — Claw  of  Simulium  vittatum,  female. 
10. — Claw  of  Simulium  piclipes,  female. 
11. — Claw  of  Simulium  virgatum,  female. 
12. — Claw  of  Simulium  UippOvorum,  female. 
13. — Claw  of  Prosimulium  fulvum,  female. 
14. — Claw  of  Prosimulium  pecuarum,  female. 
15. — Claw  of  Simulium  ochraceum,  female. 
16.-  (Maw  of  Prosimulium  j>l<tir<il<\  female. 
17. — Claw  of  Simulium  metallicum,  female. 

lv     Apex  of  basal  and  second  joint  of  hind  tarsus  of  Prosimulium   muta- 
liim.  female.     (Original.) 


Tech.  Series  26,  Bureau  of  Entomology,  U.  S.  Dept.  o1 


Plate  II 


d 


) 


17 


12 


J 


16 


,J 


15 


14 


Legs  and  Tarsal  Claws  of  Simuliid/e. 


Plate  III. 

LARVAL  CHARACTERS  OF  SIMULIIDiE. 

Fig.    1. — Mandible  of  larva  of  SimuUum  jcnningsi. 
2. — Mandible  of  larva  of  SimuUum  pictipes. 
3. — Labium  of  larva  of  Prosimulium  hirtipes. 
4. — Labium  of  larva  of  SimuUum  pictipes. 
5. — Fan  of  larva  of  SimuUum  pictipes. 
6. — Maxilla  of  larva  of  Prosimulium  hirtipes.     (Original.) 
7G 


Tech.  Series  26,  Bureau  of  Entomology,  U.  S.  Dept.  of  Agricultur 


Plate  III. 


Larval  Characters  of  Simuliid/e. 


Plate  IV. 

RESPIRATORY  FILAMENTS  OF  PUPJE  OF  SIMULIIDJE, 

Fig.   1. — Prosimulium  pecuarum. 
2. — Sim  ulium  pictipes. 
o. — Simulium  venustum. 
4. — Simulium  vittatum. 
5. — Prosimulium  hirtipes. 
6. — Simulium  meridionale.     (Original.) 

78 


Tech.  Series  26,  Bureau  of  Entomology,  U.  S.  Dept.  of  Agriculture.  PLATE    IV. 


Respiratory  Filaments  of  Pup/e  of  Simuliid/e. 


Plate  V. 

ANATOMICAL  DETAILS  OF  SIMULIIDJE. 

Fig.    1. — Femora,  tibiae,  and  basal  two  joints  of  tarsus  of  hind  leg  of  Simulium 
venustum,  male. 
2. — Same  of  Simulium  vittatum,  male. 
3. — Same  of  Simulium  virgatum,  female. 
4. — Same  of  Simulium  virgatum,  male. 
5. — Apex  of  first  and  whole  of  second  joint  of  hind  tarsus  of  Simulium 

virgatum  from  posterior  side. 
G. — Side  elevation  of  scutum  of  Simulium  notatum,  female. 
7. — Same  of  Simulium  hi  vittatum,  female. 
8. — Same  of  Simulium  ochraccum,  female. 
9. — Palpus  of  simulium  pisciddium,  female. 
10. — Last  three  tarsal  joints  in  Simulium. 
11. — Fore  tarsus  of  Simulium  parnassum,  female. 
12. — Tarsal  claw  of  Simulium  jenningsi,  male.     (Original.) 

80 


Tech.  Series  26,  Bureau  of  Entomology,  U.  S.  Dept.  of   Agriculture. 


Plate  V. 


(C 


10 


^ 


¥ 


\ 


x — 

>j 

Htm 

5 

'  V;: 

Anatomical  Details  of  Simuliid>e. 


Plate  VI. 

ANATOMICAL  DETAILS  OF  SIMULIIDiE. 

Fig.    1. — Heart  of  larva  of  Simulium  meridionale  from  ventral  aspect 
2. — Antenna  of  Simulium,  imago. 
3. — Antenna  of  Prosimulium  hirtipes,  larva. 
4. — Pupal  respiratory  filaments  of  Simulium  metallicum. 
5. — Pupal  respiratory  filaments  of  Simulium  piscicidium. 
6. — Larval  respiratory  filaments  of  Simulium  pictipes. 
7. — Portion  of  ray  of  inouth  fan  of  Prosimulium  hirtipes,  larva. 
8. — Cocoon  of  Si  in  ii  I  in  in  pictipes.     (Original.) 

82 


Tech.  Series  26,    Bureau  of  Entomology,  U.  S.  Dept.  of  Agriculture. 


Plate  VI 


Anatomical  Details  of  Simuliid/e. 


UNIVERSITY  OF  FLORIDA 


3  1262  09229  6549 


